WEBVTT 00:00:00.000 --> 00:00:02.140 When you open your fridge and, you know, grab 00:00:02.140 --> 00:00:05.120 a carton of milk, you always see that word printed 00:00:05.120 --> 00:00:07.299 right there on the label. Right, pasteurized. 00:00:07.440 --> 00:00:12.150 Exactly. And usually... We picture something 00:00:12.150 --> 00:00:14.630 incredibly precise when we read that word. Like, 00:00:14.669 --> 00:00:17.449 we imagine this pristine, sterile, perfectly 00:00:17.449 --> 00:00:20.890 clean laboratory. Oh, for sure, under those bright 00:00:20.890 --> 00:00:22.989 fluorescent lights? Yeah, where science happens 00:00:22.989 --> 00:00:25.410 strictly by the book without a single variable 00:00:25.410 --> 00:00:27.609 out of place. Well, we like our scientific history 00:00:27.609 --> 00:00:29.629 to be as clean and safe as the milk we drink, 00:00:29.629 --> 00:00:32.950 right? The popular narrative loves that idea 00:00:32.950 --> 00:00:37.179 of a lone genius in a spotless white coat. having 00:00:37.179 --> 00:00:40.719 a singular eureka moment. But if you dive into 00:00:40.719 --> 00:00:43.060 the actual life of the man behind that word on 00:00:43.060 --> 00:00:45.340 your milk carton, that pristine laboratory is 00:00:45.340 --> 00:00:47.899 suddenly covered in mud. It really is. We are 00:00:47.899 --> 00:00:50.119 stepping into a historical landscape today that's 00:00:50.119 --> 00:00:53.380 just filled with stolen ideas, bitter professional 00:00:53.380 --> 00:00:55.740 rivalries, and honestly, some shocking ethical 00:00:55.740 --> 00:00:58.600 shortcuts. Yeah, the real story is wild. So our 00:00:58.600 --> 00:01:01.100 mission for this deep dive is to strip away that 00:01:01.100 --> 00:01:03.530 glossy myth of the lone genius. We're looking 00:01:03.530 --> 00:01:05.650 at comprehensive source material detailing the 00:01:05.650 --> 00:01:08.129 life of Louis Pasteur. The so -called father 00:01:08.129 --> 00:01:11.250 of microbiology. Right. A man who fundamentally 00:01:11.250 --> 00:01:14.109 changed human health, but who also guarded a 00:01:14.109 --> 00:01:16.370 century -long secret. I mean, he deliberately 00:01:16.370 --> 00:01:19.390 hid his private laboratory notebooks. And ordered 00:01:19.390 --> 00:01:22.069 his family never to show them to anyone. Exactly. 00:01:22.230 --> 00:01:24.590 And when they were finally opened, they revealed 00:01:24.590 --> 00:01:26.969 a story that could have landed him in prison. 00:01:27.239 --> 00:01:30.739 The contrast between the public hero and the 00:01:30.739 --> 00:01:33.739 private operator is just startling. We're going 00:01:33.739 --> 00:01:36.980 to trace how a struggling, entirely unimpressive 00:01:36.980 --> 00:01:39.659 student transformed into a scientific titan. 00:01:39.920 --> 00:01:42.019 Unimpressive is almost putting it nicely. It 00:01:42.019 --> 00:01:44.500 really is. But more importantly, we are going 00:01:44.500 --> 00:01:46.900 to look at the immense personal tragedy and the 00:01:46.900 --> 00:01:49.140 fiercely competitive drive that pushed him to 00:01:49.140 --> 00:01:51.640 manipulate the very foundations of his greatest 00:01:51.640 --> 00:01:53.959 discoveries. Yeah. So to understand how Pasteur 00:01:53.959 --> 00:01:55.760 revolutionized medicine, we have to start with 00:01:55.760 --> 00:01:58.040 his beginnings, which frankly were anything but 00:01:58.040 --> 00:02:00.920 promising. Not at all. He was born in 1822 into 00:02:00.920 --> 00:02:03.859 a poor family in Dole, France. His father was 00:02:03.859 --> 00:02:06.739 a tanner working with animal hides. A very working 00:02:06.739 --> 00:02:09.719 class background. Right. And young Louis was 00:02:09.719 --> 00:02:12.620 not a child prodigy. The historical records note 00:02:12.620 --> 00:02:15.060 he actually suffered from dyslexia and dysgraphia. 00:02:15.240 --> 00:02:17.280 Yeah, he had very little interest in academics. 00:02:17.400 --> 00:02:20.580 He preferred fishing or sketching portraits of 00:02:20.580 --> 00:02:23.539 his neighbors using pastels. Which is so funny 00:02:23.539 --> 00:02:25.520 to think about. And when he took his general 00:02:25.520 --> 00:02:28.460 science degree examination in 1842, his official 00:02:28.460 --> 00:02:31.120 grade in chemistry was literally recorded as 00:02:31.120 --> 00:02:34.639 mediocre. Mediocre. He was, by all institutional 00:02:34.639 --> 00:02:37.900 metrics, a completely average, unremarkable student. 00:02:38.060 --> 00:02:40.759 Okay, let's unpack this. Because a guy who has 00:02:40.759 --> 00:02:43.900 literally graded mediocre in chemistry goes on 00:02:43.900 --> 00:02:46.620 to make what many historians consider his greatest 00:02:46.620 --> 00:02:49.240 foundational scientific discovery just a few 00:02:49.240 --> 00:02:52.780 years later. Right, in 1848. Yeah, 1848. He was 00:02:52.780 --> 00:02:55.039 examining a chemical called tartrate. It's a 00:02:55.039 --> 00:02:57.460 salt that builds up on the inside of wine casks 00:02:57.460 --> 00:02:59.659 during fermentation. And scientists at the time 00:02:59.659 --> 00:03:02.639 were totally baffled by it. Because natural tartrate 00:03:02.639 --> 00:03:05.490 bent polarized light. but synthetic tartrate 00:03:05.490 --> 00:03:08.009 created in a lab did not, even though their chemical 00:03:08.009 --> 00:03:10.550 ingredients were totally identical. So Pasteur 00:03:10.550 --> 00:03:12.669 looks at this and discovers molecular chirality. 00:03:12.889 --> 00:03:15.969 And for you listening, think of molecular chirality 00:03:15.969 --> 00:03:18.189 like a pair of winter gloves. That's a great 00:03:18.189 --> 00:03:20.449 way to picture it. Right. A left glove and a 00:03:20.449 --> 00:03:22.750 right glove possess the exact same components. 00:03:23.270 --> 00:03:25.349 Same fingers, same thumb, same wool material. 00:03:25.469 --> 00:03:28.069 But you absolutely cannot superimpose a left 00:03:28.069 --> 00:03:30.469 glove perfectly onto a right hand. Exactly. They 00:03:30.469 --> 00:03:32.969 are mirror images. And Pasteur discovers that 00:03:32.969 --> 00:03:35.990 microscopic molecules can exist as left -handed 00:03:35.990 --> 00:03:38.370 and right -handed mirror images, too. Which was 00:03:38.370 --> 00:03:41.030 groundbreaking. But how does a mediocre chemistry 00:03:41.030 --> 00:03:44.409 student figure out a microscopic structural mystery 00:03:44.409 --> 00:03:47.050 that the greatest scientific minds of Europe 00:03:47.050 --> 00:03:49.650 just completely missed? Well, what's fascinating 00:03:49.650 --> 00:03:52.370 here is that his perceived academic weaknesses 00:03:52.370 --> 00:03:55.210 actually forged his greatest observational strengths. 00:03:55.389 --> 00:03:58.210 How so? His background in art, spending all those 00:03:58.210 --> 00:04:00.889 hours sketching those pastel portraits, it trained 00:04:00.889 --> 00:04:03.889 his eye to notice incredibly subtle variations 00:04:03.889 --> 00:04:07.509 in shape, shading, geometry. Oh, wow. So he was 00:04:07.509 --> 00:04:09.310 seeing things others literally couldn't see. 00:04:09.810 --> 00:04:12.490 Exactly. When other chemists looked at tartrate 00:04:12.490 --> 00:04:15.069 crystals under a microscope, they just saw a 00:04:15.069 --> 00:04:19.040 homogenous chemical pile. But Pasteur looked 00:04:19.040 --> 00:04:22.279 through the lens and saw physical three -dimensional 00:04:22.279 --> 00:04:25.339 architecture. That is wild. He noticed that the 00:04:25.339 --> 00:04:27.639 synthetic mixture was actually composed of two 00:04:27.639 --> 00:04:30.699 distinct types of crystals. Half of them had 00:04:30.699 --> 00:04:33.660 tiny asymmetric faces leaning to the right, and 00:04:33.660 --> 00:04:35.779 the other half had faces leaning to the left. 00:04:35.879 --> 00:04:38.850 So they were chiral. Yes. and he spent hours 00:04:38.850 --> 00:04:41.769 physically separating them with a needle and 00:04:41.769 --> 00:04:45.310 tweezers into two distinct piles based purely 00:04:45.310 --> 00:04:47.930 on their visual geometry. Wait, he is literally 00:04:47.930 --> 00:04:51.250 doing microscopic sorting by hand? By hand, relying 00:04:51.250 --> 00:04:53.930 entirely on an artist's eye for detail. That's 00:04:53.930 --> 00:04:55.829 insane. And if we connect this to the bigger 00:04:55.829 --> 00:04:58.490 picture, this panstaking sorting established 00:04:58.490 --> 00:05:00.850 the entire foundation of structural chemistry. 00:05:01.149 --> 00:05:03.750 Because it proved shape matters. Right. He proved 00:05:03.750 --> 00:05:06.230 that the physical three -dimensional shape of 00:05:06.230 --> 00:05:08.290 a molecule dictates how it interacts with the 00:05:08.290 --> 00:05:10.730 world just as much as its chemical ingredients 00:05:10.730 --> 00:05:13.529 do. So a left -handed molecule interacts with 00:05:13.529 --> 00:05:16.209 light differently than a right -handed one. Exactly. 00:05:16.569 --> 00:05:18.850 It fundamentally changed how we understand the 00:05:18.850 --> 00:05:21.290 basic building blocks of matter. But here is 00:05:21.290 --> 00:05:23.980 where the story makes a massive pivot. because 00:05:23.980 --> 00:05:26.079 we have a chemist obsessed with the geometry 00:05:26.079 --> 00:05:29.579 of crystals. How does he jump from analyzing 00:05:29.579 --> 00:05:32.360 the shape of salt to, you know, revolutionizing 00:05:32.360 --> 00:05:34.800 biology and disease? It's a big leap. It turns 00:05:34.800 --> 00:05:38.680 out Pasteur noticed a crucial pattern. In nature, 00:05:39.139 --> 00:05:42.180 only living organisms seem to produce these asymmetrical 00:05:42.180 --> 00:05:45.060 one -handed molecules. While synthesized chemicals 00:05:45.060 --> 00:05:48.600 produced an even 50 -50 mix. Right, so in Pasteur's 00:05:48.600 --> 00:05:51.500 mind, microscopic asymmetry became the ultimate 00:05:51.500 --> 00:05:54.459 signature of life. And that underlying philosophy 00:05:54.459 --> 00:05:57.339 perfectly primed him for what happened in 1856. 00:05:57.560 --> 00:05:59.420 Right, the beetroot alcohol. Yeah, he was working 00:05:59.420 --> 00:06:01.579 in the industrial town of Lille when a local 00:06:01.579 --> 00:06:04.699 manufacturer named M. Bigot approached him. Bigot 00:06:04.699 --> 00:06:07.199 had a massive problem. His factory's beetroot 00:06:07.199 --> 00:06:10.259 alcohol was inexplicably turning sour and just 00:06:10.259 --> 00:06:13.199 ruining his business. And at the time, the absolute 00:06:13.199 --> 00:06:15.360 consensus in the scientific community was that 00:06:15.360 --> 00:06:17.920 fermentation was a purely chemical process of 00:06:17.920 --> 00:06:20.360 decomposition. They believed the liquid was just 00:06:20.360 --> 00:06:22.720 naturally breaking down and rotting. And that 00:06:22.720 --> 00:06:25.319 yeast was just a dead chemical byproduct of that 00:06:25.319 --> 00:06:28.639 rot. Right. But because Pasteur believes asymmetry 00:06:28.639 --> 00:06:31.560 equals life, he puts the souring alcohol under 00:06:31.560 --> 00:06:33.899 his microscope and he doesn't see a chemical 00:06:33.899 --> 00:06:37.019 breakdown. He sees living things. Yes. He sees 00:06:37.019 --> 00:06:40.660 tiny, living, asymmetric yeast cells. He realizes 00:06:40.660 --> 00:06:43.459 the yeast isn't a byproduct of death. The yeast 00:06:43.459 --> 00:06:46.040 is a living organism actively eating the beetroot 00:06:46.040 --> 00:06:48.579 sugar and excreting alcohol. And when the vat 00:06:48.579 --> 00:06:51.980 goes sour, it's because a different rod -shaped 00:06:51.980 --> 00:06:55.040 contaminating microorganism has invaded the vat 00:06:55.040 --> 00:06:58.199 and is producing lactic acid instead. So understanding 00:06:58.199 --> 00:07:00.639 that biological mechanism that specific living 00:07:00.639 --> 00:07:02.819 microbes cause specific types of fermentation 00:07:02.819 --> 00:07:05.589 or spoilage allowed him to engineer a brilliantly 00:07:05.589 --> 00:07:08.009 simple solution. Which we still use today. Exactly. 00:07:08.430 --> 00:07:10.490 He discovered that heating the liquid to a specific 00:07:10.490 --> 00:07:13.050 temperature between 60 and 100 degrees Celsius 00:07:13.050 --> 00:07:16.110 was lethal to the invading bacteria, but gentle 00:07:16.110 --> 00:07:18.389 enough not to destroy the chemical profile of 00:07:18.389 --> 00:07:21.250 the liquid itself. This process, pasteurization, 00:07:21.689 --> 00:07:23.910 single -handedly saved the French wine, beer, 00:07:24.029 --> 00:07:26.509 and dairy industries from catastrophic spoilage. 00:07:26.790 --> 00:07:29.930 But proving that invisible, living things were 00:07:29.930 --> 00:07:33.829 floating around, causing wine to sour, put directly 00:07:33.829 --> 00:07:36.509 in the crosshairs of the biggest scientific heavyweight 00:07:36.509 --> 00:07:39.310 bout of the 19th century. Oh yeah, the debate 00:07:39.310 --> 00:07:42.790 over spontaneous generation. Right, the prevailing 00:07:42.790 --> 00:07:45.629 doctrine held that life could spontaneously arise 00:07:45.629 --> 00:07:48.110 from non -living matter under the right conditions. 00:07:48.389 --> 00:07:51.610 Which was a very widely held belief. I have to 00:07:51.610 --> 00:07:53.490 push back on the historical context here though, 00:07:53.790 --> 00:07:56.189 because spontaneous generation sounds utterly 00:07:56.189 --> 00:07:58.649 absurd to a modern listener. It does sound like 00:07:58.649 --> 00:08:02.360 magic to us. Yeah. Why did highly educated, eminent 00:08:02.360 --> 00:08:04.939 scientists believe that a pile of dust or a piece 00:08:04.939 --> 00:08:07.879 of dead meat could just magically birth a living, 00:08:07.879 --> 00:08:10.240 breathing organism? Well, we have to strip away 00:08:10.240 --> 00:08:12.920 our modern understanding of microbiology to see 00:08:12.920 --> 00:08:15.459 it from their perspective. When a 19th century 00:08:15.459 --> 00:08:17.959 scientist left a piece of spoiling meat on a 00:08:17.959 --> 00:08:20.660 table, maggots appeared a few days later. Right. 00:08:20.759 --> 00:08:23.399 When they left broth out, mold materialized out 00:08:23.399 --> 00:08:25.500 of nowhere. They couldn't see the microscopic 00:08:25.500 --> 00:08:28.019 fly eggs or the airborne fungal spores. Because 00:08:28.019 --> 00:08:30.819 they were too small. Exactly. So the observational 00:08:30.819 --> 00:08:33.580 evidence, to the naked eye at least, strongly 00:08:33.580 --> 00:08:36.419 suggested the decaying matter itself was generating 00:08:36.419 --> 00:08:39.879 the life. Wow. This wasn't a fringe tinfoil hat 00:08:39.879 --> 00:08:42.759 theory. It was vigorously defended by figures 00:08:42.759 --> 00:08:46.019 like Felix Archimede Pouche. He was the esteemed 00:08:46.019 --> 00:08:48.279 director of the Rouen Museum of Natural History, 00:08:48.279 --> 00:08:51.340 and he published massive volumes, quote unquote, 00:08:51.740 --> 00:08:54.460 proving the phenomenon. So if we use an analogy 00:08:54.460 --> 00:08:56.460 for you listening, it's like leaving a piece 00:08:56.460 --> 00:08:59.600 of cheese in a locked, dark room. coming back 00:08:59.600 --> 00:09:02.259 to find mice eating it, and concluding that the 00:09:02.259 --> 00:09:03.960 cheese must have physically transformed into 00:09:03.960 --> 00:09:06.139 mice, simply because you didn't see them squeeze 00:09:06.139 --> 00:09:08.220 under the door. That is exactly the logic they 00:09:08.220 --> 00:09:10.399 were using. So, Pasteur has to prove a negative. 00:09:11.080 --> 00:09:13.139 He has to prove the air itself doesn't magically 00:09:13.139 --> 00:09:15.659 create life, but rather that the air serves as 00:09:15.659 --> 00:09:18.299 a transport system for invisible living invaders. 00:09:18.419 --> 00:09:20.940 And he achieves this through a very elegant design. 00:09:21.159 --> 00:09:24.000 The famous swan neck flask experiment. He fills 00:09:24.000 --> 00:09:26.980 a glass flask with nutrient broth and boils it 00:09:26.980 --> 00:09:29.539 to kill everything inside. But instead of sealing 00:09:29.539 --> 00:09:31.980 it, he heats the glass neck of the flask and 00:09:31.980 --> 00:09:34.879 pulls it into a long, thin S -shaped curve that 00:09:34.879 --> 00:09:37.899 remains open to the air. And the physical mechanism 00:09:37.899 --> 00:09:40.860 of that S -curve is just brilliant. The broth 00:09:40.860 --> 00:09:43.919 inside that open flask never spoiled. Months 00:09:43.919 --> 00:09:47.200 passed, and it remained perfectly sterile. Because, 00:09:47.600 --> 00:09:50.240 and think of that swan neck curve, like a medieval 00:09:50.240 --> 00:09:53.460 castle's moat, the oxygen, which the spontaneous 00:09:53.460 --> 00:09:55.940 generation camp claimed was the vital spark of 00:09:55.940 --> 00:09:58.620 life, can easily pass over the moat and travel 00:09:58.620 --> 00:10:00.559 down the neck into the broth. Right, the air 00:10:00.559 --> 00:10:03.259 gets in. But the invading microscopic armies, 00:10:03.559 --> 00:10:05.860 the dust particles carrying bacterial spores, 00:10:06.299 --> 00:10:08.620 they're heavy. As they travel through the curved 00:10:08.620 --> 00:10:11.360 neck, gravity pulls them down, and they get trapped 00:10:11.360 --> 00:10:13.679 in the lowest part of the slippery glass S -curve. 00:10:13.820 --> 00:10:16.200 They can't climb up the steep interior walls 00:10:16.200 --> 00:10:18.759 to reach the sterile broth waiting inside. But 00:10:18.759 --> 00:10:22.200 the absolute second pastor tilts the flask, allowing 00:10:22.200 --> 00:10:24.679 the sterile broth to wash up into the curve and 00:10:24.679 --> 00:10:27.259 touch the trapped dust. The broth instantly clouds 00:10:27.259 --> 00:10:30.139 with bacterial life and spoils. Bam. Yeah. He 00:10:30.139 --> 00:10:32.559 presented these findings in 1862, winning the 00:10:32.559 --> 00:10:35.200 prestigious Alhumbert Prize. He stood before 00:10:35.200 --> 00:10:37.440 the Scientific Academy and delivered a mortal 00:10:37.440 --> 00:10:39.740 blow to the theory, proving definitively that 00:10:39.740 --> 00:10:42.419 life only comes from pre -existing life. So he 00:10:42.419 --> 00:10:45.179 becomes a national hero. He saved the agricultural 00:10:45.179 --> 00:10:48.759 economy and rewrote biology. Naturally, the French 00:10:48.759 --> 00:10:51.360 government sends their star scientist to Allée 00:10:51.360 --> 00:10:54.679 because a mysterious, devastating disease is 00:10:54.679 --> 00:10:57.100 wiping out the nation's silkworms. And this is 00:10:57.100 --> 00:10:58.840 where the narrative usually speeds up in the 00:10:58.840 --> 00:11:00.740 textbooks. Yeah, but the source material shows 00:11:00.740 --> 00:11:04.539 Pasteur floundered here. He spent five grueling 00:11:04.539 --> 00:11:07.620 years in the south of France making massive scientific 00:11:07.620 --> 00:11:10.320 errors. His initial arrogance really blinded 00:11:10.320 --> 00:11:13.460 him. He stubbornly denied the disease was parasitic 00:11:13.460 --> 00:11:16.970 at first. Which is shocking. It is. And he completely 00:11:16.970 --> 00:11:20.049 confused two separate ailments, a parasitic infection 00:11:20.049 --> 00:11:23.169 called pay -brain and a distinct intestinal disease 00:11:23.169 --> 00:11:25.929 called flashery. He just assumed it was a genetic 00:11:25.929 --> 00:11:28.250 weakness in the worms. He had to suffer through 00:11:28.250 --> 00:11:30.590 years of failure before he finally applied his 00:11:30.590 --> 00:11:32.750 microscopic expertise to the problem. Right, 00:11:32.750 --> 00:11:34.909 going back to what he was good at. Exactly. He 00:11:34.909 --> 00:11:36.929 discovered he could crush the female moths after 00:11:36.929 --> 00:11:39.070 they laid their eggs and examined their bodily 00:11:39.070 --> 00:11:41.909 fluids under a microscope. If he saw the glowing 00:11:41.909 --> 00:11:44.690 microscopic disease corpuscles, he knew that 00:11:44.690 --> 00:11:46.870 specific batch of eggs was infected and had to 00:11:46.870 --> 00:11:50.169 be destroyed. So by microscopically screening 00:11:50.169 --> 00:11:53.809 the eggs, he ensured only healthy silkworms reproduced, 00:11:54.029 --> 00:11:56.240 which saved the industry. But that five -year 00:11:56.240 --> 00:11:58.440 struggle was his crucible. Yeah, it forced him 00:11:58.440 --> 00:12:01.139 to transition from a chemist observing fermentation 00:12:01.139 --> 00:12:03.919 into an epidemiologist tracking the transmission 00:12:03.919 --> 00:12:06.259 of contagious pathogens through a population. 00:12:06.539 --> 00:12:08.940 And while he is systematically saving the nation's 00:12:08.940 --> 00:12:12.480 agricultural livelihoods, a devastating invisible 00:12:12.480 --> 00:12:15.500 enemy is ravaging his own home. This part is 00:12:15.500 --> 00:12:18.320 so heartbreaking. It is. Pasteur and his wife 00:12:18.320 --> 00:12:21.610 Marie had five children. And the historical records 00:12:21.610 --> 00:12:25.009 highlight a staggering, almost unimaginable personal 00:12:25.009 --> 00:12:28.090 tragedy. Three of those five children died of 00:12:28.090 --> 00:12:30.710 typhoid, a water -borne bacterial infection. 00:12:30.970 --> 00:12:33.129 And the psychological weight of that loss just 00:12:33.129 --> 00:12:35.389 cannot be overstated. It caused a fundamental, 00:12:35.629 --> 00:12:37.730 permanent shift in his life's trajectory. He 00:12:37.730 --> 00:12:39.590 gave up on the industrial stuff, right? Completely. 00:12:39.870 --> 00:12:42.610 He abandoned industrial chemistry, wine spoilage, 00:12:42.710 --> 00:12:45.610 silkworms. He pivoted his immense intellect and 00:12:45.610 --> 00:12:47.889 his laboratory entirely toward human immunology 00:12:47.889 --> 00:12:50.490 and infectious diseases. The tragic loss of his 00:12:50.490 --> 00:12:53.149 daughters fueled an absolute uncompromising war 00:12:53.149 --> 00:12:55.870 against the microscopic world. And this crusade 00:12:55.870 --> 00:12:58.690 leads to his groundbreaking work in vaccines. 00:12:58.909 --> 00:13:00.990 Which actually begins with an accident involving 00:13:00.990 --> 00:13:03.450 chicken cholera. Right. He's studying the deadly 00:13:03.450 --> 00:13:06.389 bacteria in his lab. He goes away on a vacation. 00:13:06.700 --> 00:13:08.820 or attends a wedding, depending on the historical 00:13:08.820 --> 00:13:11.779 account, and instructs his assistant, Emile Roux, 00:13:12.320 --> 00:13:14.679 to inject a batch of chickens with the cholera 00:13:14.679 --> 00:13:17.220 culture. But Roux forgets. Roux forgets. The 00:13:17.220 --> 00:13:19.580 culture sits out on the laboratory bench exposed 00:13:19.580 --> 00:13:23.080 to the air for weeks. When Roux finally remembers 00:13:23.080 --> 00:13:25.399 and injects the chickens with this old, neglected 00:13:25.399 --> 00:13:28.279 culture, something strange happens. The chickens 00:13:28.279 --> 00:13:30.639 show mild symptoms, but they don't die. They 00:13:30.639 --> 00:13:33.139 completely recover. Here's where it gets really 00:13:33.139 --> 00:13:35.570 interesting. Pasteur's team later takes those 00:13:35.570 --> 00:13:38.870 exact same chickens and injects them with a fresh, 00:13:39.049 --> 00:13:41.929 deadly, fully virulent batch of cholera bacteria. 00:13:42.149 --> 00:13:44.549 A batch that should kill them in hours. But they 00:13:44.549 --> 00:13:46.549 survive. They don't even get a sniffle. They 00:13:46.549 --> 00:13:49.409 are totally immune. And to understand the mechanism 00:13:49.409 --> 00:13:52.049 here, think of that old air -exposed bacteria 00:13:52.049 --> 00:13:55.009 like a sparring partner in a boxing gym. OK, 00:13:55.029 --> 00:13:57.450 I like this analogy. Right. Because the bacteria 00:13:57.450 --> 00:14:00.450 sat out in the harsh oxygen for weeks, it became 00:14:00.450 --> 00:14:03.600 stressed and physically weakened. When injected, 00:14:03.879 --> 00:14:06.159 This weakened sparring partner isn't strong enough 00:14:06.159 --> 00:14:08.840 to knock you out, but fighting it teaches your 00:14:08.840 --> 00:14:11.059 immune system all the necessary moves, all the 00:14:11.059 --> 00:14:13.600 dodges, everything it needs to build a targeted 00:14:13.600 --> 00:14:16.899 defense. So when the real heavyweight champion 00:14:16.899 --> 00:14:19.419 virus actually steps into the ring later, your 00:14:19.419 --> 00:14:22.179 immune system already knows exactly how to destroy 00:14:22.179 --> 00:14:25.220 it. Exactly. And Pasteur recognized the magnitude 00:14:25.220 --> 00:14:27.700 of this accident immediately. I mean, decades 00:14:27.700 --> 00:14:30.519 earlier, Edward Jenner had discovered that exposing 00:14:30.519 --> 00:14:33.809 people to cowpox, which is a naturally occurring 00:14:33.809 --> 00:14:37.330 milder animal virus protected them against deadly 00:14:37.330 --> 00:14:40.009 human smallpox. Right. The first real vaccine. 00:14:40.330 --> 00:14:42.809 Yes. But Pasteur realized they were no longer 00:14:42.809 --> 00:14:44.809 bound by the limits of nature. They didn't have 00:14:44.809 --> 00:14:47.169 to wander around hoping to find naturally weak 00:14:47.169 --> 00:14:49.649 diseases. They could artificially create them 00:14:49.649 --> 00:14:51.690 in a laboratory. Just make their own sparring 00:14:51.690 --> 00:14:53.909 partner. Exactly. They could take a lethal pathogen 00:14:53.909 --> 00:14:56.330 and intentionally weaken it, attenuate it by 00:14:56.330 --> 00:14:59.049 exposing it to environmental stressors like oxygen 00:14:59.049 --> 00:15:02.149 or heat. And Pasteur actually generously coined 00:15:02.149 --> 00:15:05.799 the gen... term vaccine to honor Jenner's pioneering 00:15:05.799 --> 00:15:09.279 cowpox work derived from Vaca, the Latin word 00:15:09.279 --> 00:15:12.820 for cow. Which is a nice nod to history. It is. 00:15:13.100 --> 00:15:15.940 And this revelation that humans could engineer 00:15:15.940 --> 00:15:19.179 their own biological armor -led pasture to his 00:15:19.179 --> 00:15:22.600 most legendary public triumphs. But it also pushed 00:15:22.600 --> 00:15:25.019 him into a dark territory of massive ethical 00:15:25.019 --> 00:15:28.110 shortcuts and deliberate deception. Yes. The 00:15:28.110 --> 00:15:30.090 secrets he ordered his family to keep completely 00:15:30.090 --> 00:15:32.330 hidden from the world. For over a century, the 00:15:32.330 --> 00:15:35.169 public was fed a highly sanitized, heroic version 00:15:35.169 --> 00:15:38.509 of events. Very sanitized. Take the famous 1881 00:15:38.509 --> 00:15:40.769 Puy -le -Four public experiment, for example. 00:15:40.809 --> 00:15:42.950 The one with the anthrax. Yeah, anthrax was decimating 00:15:42.950 --> 00:15:45.549 sheep and cattle across Europe. Pasteur announced 00:15:45.549 --> 00:15:48.210 a massive, highly publicized trial, claiming 00:15:48.210 --> 00:15:50.370 he had successfully vaccinated livestock using 00:15:50.370 --> 00:15:53.279 his signature method. A quote -unquote live vaccine 00:15:53.279 --> 00:15:55.620 weakened purely by exposure to oxygen. The press 00:15:55.620 --> 00:15:58.879 loved this. Oh, journalists, politicians, scientists 00:15:58.879 --> 00:16:01.440 all gathered to watch. And the vaccinated animals 00:16:01.440 --> 00:16:04.059 lived while the unvaccinated control group died. 00:16:04.419 --> 00:16:07.740 It was hailed as a spectacular, unambiguous triumph 00:16:07.740 --> 00:16:10.860 of Pasteur's oxygen attenuation method. Exactly. 00:16:11.259 --> 00:16:14.580 Then we have the rabies vaccine in 1885. Rabies 00:16:14.580 --> 00:16:16.960 was a death sentence. It is a virus that travels 00:16:16.960 --> 00:16:20.240 slowly, millimeter by millimeter, up the perfilineurs. 00:16:20.409 --> 00:16:23.129 until it reaches the brain, causing terrifying 00:16:23.129 --> 00:16:25.750 neurological decay and inevitable death. Just 00:16:25.750 --> 00:16:28.690 horrific. And a nine -year -old boy named Joseph 00:16:28.690 --> 00:16:31.970 Meister is brought to Pasteur's lab, having been 00:16:31.970 --> 00:16:34.889 savagely mauled by a rabbit dog. Now Pasteur 00:16:34.889 --> 00:16:37.990 is a chemist. He holds no medical degree. Administering 00:16:37.990 --> 00:16:40.090 an experimental treatment to a child could literally 00:16:40.090 --> 00:16:42.309 mean prison time if he fails. But he takes the 00:16:42.309 --> 00:16:45.049 gamble. He does. Over 11 days, he administers 00:16:45.049 --> 00:16:47.889 13 inoculations of Radies virus to the boy. And 00:16:47.889 --> 00:16:50.049 the mechanism behind those 13 shots relies on 00:16:50.049 --> 00:16:52.129 that slow moving nature of the rabies virus you 00:16:52.129 --> 00:16:54.590 mentioned. Pasteur's protocol involved injecting 00:16:54.590 --> 00:16:57.289 viral spinal cord extracts, starting with a heavily 00:16:57.289 --> 00:16:59.610 weakened strain and progressively administering 00:16:59.610 --> 00:17:02.669 stronger, more virulent doses each day. So building 00:17:02.669 --> 00:17:06.210 up the immunity slowly. Right. The goal was to 00:17:06.210 --> 00:17:08.470 force the boy's immune system to build an army 00:17:08.470 --> 00:17:11.509 of antibodies fast enough to intercept the actual 00:17:11.509 --> 00:17:14.130 street virus before it could crawl up the nervous 00:17:14.130 --> 00:17:16.230 system to the brain. And the protocol worked. 00:17:16.519 --> 00:17:20.000 Joseph Meister lived. The story became a global 00:17:20.000 --> 00:17:22.640 sensation and the massive funding that poured 00:17:22.640 --> 00:17:25.039 in led to the founding of the Pasteur Institute. 00:17:25.220 --> 00:17:27.680 It's the ultimate hero's journey. Until we fast 00:17:27.680 --> 00:17:30.900 forward to 1995. Right. A historian of science 00:17:30.900 --> 00:17:34.240 named Gerald L. Gyson publishes a bombshell book. 00:17:35.140 --> 00:17:37.859 He had finally gained access to Pasteur's secret 00:17:37.859 --> 00:17:41.339 private laboratory notebooks. The exact notebooks 00:17:41.339 --> 00:17:44.279 Pasteur explicitly forbade his descendants from 00:17:44.279 --> 00:17:46.859 ever showing to anyone. And opening those pages 00:17:46.859 --> 00:17:49.599 shattered the pristine myth. The notebooks proved 00:17:49.599 --> 00:17:52.000 unequivocally that Pasteur systematically lied 00:17:52.000 --> 00:17:54.799 to the public, the press, and his fellow scientists. 00:17:55.079 --> 00:17:57.099 This raises an important question about myth 00:17:57.099 --> 00:17:59.680 -making in science. Let's look at the anthrax 00:17:59.680 --> 00:18:02.740 trial at Puyla IV. The notebooks reveal he didn't 00:18:02.740 --> 00:18:05.359 use his famous oxygen -weakened method for that 00:18:05.359 --> 00:18:07.819 public demonstration at all. Wait, really? Really. 00:18:08.059 --> 00:18:10.640 His oxygen method was unstable and just wasn't 00:18:10.640 --> 00:18:13.299 ready. Instead, he secretly used a completely 00:18:13.299 --> 00:18:16.160 different technique, chemical inactivation using 00:18:16.160 --> 00:18:19.059 a poison called potassium dichromate. Oh, wow. 00:18:19.279 --> 00:18:22.039 Yeah. Instead of letting the bacteria slowly 00:18:22.039 --> 00:18:24.960 weaken in the air, this chemical process aggressively 00:18:24.960 --> 00:18:28.059 maimed the anthrax spores. But the devastating 00:18:28.059 --> 00:18:30.099 part is where that chemical method came from, 00:18:30.099 --> 00:18:32.799 right? Exactly. That chemical method was developed 00:18:32.799 --> 00:18:35.019 by his own assistant, Charles Chamberlain, and 00:18:35.019 --> 00:18:37.720 it was almost perfectly identical to the proprietary 00:18:37.720 --> 00:18:40.859 method of his fierce rival, a veterinarian named 00:18:40.859 --> 00:18:43.920 Henry Toussaint. So Pasteur essentially commandeered 00:18:43.920 --> 00:18:47.259 his rival's chemical technique to guarantee success 00:18:47.259 --> 00:18:49.920 under the spotlight. Yes. He stood before the 00:18:49.920 --> 00:18:52.299 world's press claiming the victory proved his 00:18:52.299 --> 00:18:55.700 own oxygen theory and deliberately buried Tucson's 00:18:55.700 --> 00:18:57.880 contribution. And the notebooks revealed an even 00:18:57.880 --> 00:19:00.599 darker reality regarding the Joseph Meister Rabies 00:19:00.599 --> 00:19:02.740 case. Right. Before injecting that nine -year 00:19:02.740 --> 00:19:04.720 -old boy with a potentially lethal experimental 00:19:04.720 --> 00:19:08.019 virus, Pasteur publicly assured the medical community 00:19:08.019 --> 00:19:10.539 that the protocol had been exhaustively tested 00:19:10.539 --> 00:19:13.720 and proven safe on 50 dogs. But the private notebook 00:19:13.720 --> 00:19:16.759 showed he had only tested that specific, progressively 00:19:16.759 --> 00:19:20.640 stronger 13 -shot sequence on exactly 11 dogs. 00:19:21.259 --> 00:19:25.039 Just 11 dogs. Yeah. And the ethics of this experimentation 00:19:25.039 --> 00:19:28.140 caused severe friction even within his own laboratory 00:19:28.140 --> 00:19:31.359 walls. His closest collaborator, Emile Roux, 00:19:31.640 --> 00:19:34.119 who actually possessed a medical degree and did 00:19:34.119 --> 00:19:36.480 the crucial heavy lifting in developing the rabies 00:19:36.480 --> 00:19:39.619 vaccine, was so appalled by the lack of sufficient 00:19:39.619 --> 00:19:42.559 animal data that he absolutely refused used to 00:19:42.559 --> 00:19:45.519 participate in the human trial. Wow. So his own 00:19:45.519 --> 00:19:47.900 team turned against the idea. Ru walked away, 00:19:48.140 --> 00:19:50.380 believing that testing such an unproven protocol 00:19:50.380 --> 00:19:52.779 on a human child was scientifically reckless 00:19:52.779 --> 00:19:55.680 and fundamentally unjust. I have to raise a sharp 00:19:55.680 --> 00:19:57.680 pushback here on the ethics, though. OK, go ahead. 00:19:57.819 --> 00:19:59.599 Put yourself in that laboratory. Yeah. You're 00:19:59.599 --> 00:20:01.599 looking at a nine -year -old boy who has been 00:20:01.599 --> 00:20:05.019 mauled by a rabid dog without treatment. that 00:20:05.019 --> 00:20:08.019 boy is absolutely 100 % going to die one of the 00:20:08.019 --> 00:20:10.400 most agonizing deaths known to humanity. That's 00:20:10.400 --> 00:20:12.660 true. Does it really matter in that desperate 00:20:12.660 --> 00:20:15.940 moment whether Pasteur tested 11 dogs or 50? 00:20:16.380 --> 00:20:19.079 Are we sitting in the safety of the 21st century, 00:20:19.740 --> 00:20:22.680 unfairly judging a frantic 19th century rescue 00:20:22.680 --> 00:20:25.559 mission by the bureaucratic standards of modern 00:20:25.559 --> 00:20:28.849 FDA clinical trials? It is a profound ethical 00:20:28.849 --> 00:20:31.549 dilemma and, you know, historians continue to 00:20:31.549 --> 00:20:34.309 debate it. Meister survived and that risky gamble 00:20:34.309 --> 00:20:36.849 paved the way for a vaccine that saved countless 00:20:36.849 --> 00:20:39.329 lives. Right. But the core issue revealed by 00:20:39.329 --> 00:20:41.609 the notebooks isn't just that Passer took a desperate 00:20:41.609 --> 00:20:44.789 risk to save a dying child. It's the systematic 00:20:44.789 --> 00:20:47.470 calculated suppression of the truth surrounding 00:20:47.470 --> 00:20:50.509 his work. The cover up. Exactly. He deliberately 00:20:50.509 --> 00:20:52.789 erased the essential contributions of his assistants 00:20:52.789 --> 00:20:55.869 like Chamberlain and Rue and ruthlessly discredited 00:20:55.869 --> 00:20:59.509 rivals like He manipulated the data to secure 00:20:59.509 --> 00:21:02.589 his own funding, ensure his own legacy, and position 00:21:02.589 --> 00:21:05.750 himself as the lone infallible savior of French 00:21:05.750 --> 00:21:07.849 science. So what does this all mean? When we 00:21:07.849 --> 00:21:10.490 trace the full arc of this deep dive, it is astonishing. 00:21:11.109 --> 00:21:13.609 We started with a dysgraphic boy in rural France 00:21:13.609 --> 00:21:16.309 who preferred sketching pastel portraits over 00:21:16.309 --> 00:21:18.789 studying chemistry. We watched him apply that 00:21:18.789 --> 00:21:22.670 artist's eye to sort microscopic crystals, accidentally 00:21:22.670 --> 00:21:25.640 inventing structural chemistry. an incredible 00:21:25.640 --> 00:21:29.519 leap. We saw how his belief that asymmetry equaled 00:21:29.519 --> 00:21:31.839 life allowed him to deduce that yeast was a living 00:21:31.839 --> 00:21:34.960 creature saving the food supply. We witnessed 00:21:34.960 --> 00:21:38.319 a grieving father lose three children to invisible 00:21:38.319 --> 00:21:41.259 pathogens, driving him to declare total war on 00:21:41.259 --> 00:21:43.859 disease. A war that changed the world. And finally 00:21:43.859 --> 00:21:47.140 we saw a fiercely competitive, brilliant, deeply 00:21:47.140 --> 00:21:49.660 flawed man who was willing to steal chemical 00:21:49.660 --> 00:21:52.940 methods, bend experimental protocols, and risk 00:21:52.940 --> 00:21:55.160 prison to force his life -saving cures into the 00:21:55.160 --> 00:21:58.220 world. It leaves us with a fascinating and perhaps 00:21:58.220 --> 00:22:00.380 slightly uncomfortable final thought to ponder. 00:22:00.839 --> 00:22:03.839 If Louis Pasteur's greatest, most world -altering 00:22:03.839 --> 00:22:05.839 burk -throughs, the ones that quite literally 00:22:05.839 --> 00:22:08.359 laid the foundation of modern medicine, secretly 00:22:08.359 --> 00:22:10.640 relied on the uncredited labor, the stolen chemicals, 00:22:10.799 --> 00:22:12.440 and the suppressed methods of his assistants 00:22:12.440 --> 00:22:15.460 and rivals, how many other foundational discoveries 00:22:15.460 --> 00:22:17.339 enshrined in our history books are actually the 00:22:17.339 --> 00:22:21.160 result of messy, suppressed, deeply human collaboration, 00:22:21.660 --> 00:22:23.599 rather than the sudden brilliant stroke of a 00:22:23.599 --> 00:22:26.259 lone genius? That is a wild thought. It really 00:22:26.259 --> 00:22:27.819 makes you think differently the next time you 00:22:27.819 --> 00:22:29.940 open your fridge. You look at that carton of 00:22:29.940 --> 00:22:32.740 milk and that word pasteurized. It doesn't just 00:22:32.740 --> 00:22:35.039 stand for a perfectly sterile, clean laboratory 00:22:35.039 --> 00:22:38.640 anymore. It stands for a history that is messy, 00:22:39.299 --> 00:22:41.720 fraught with human ambition and far more complicated 00:22:41.720 --> 00:22:42.779 than the label that's on.