Yes, my apologies, I didn't think the whole drop in infant mortality was due to incubators. I was referencing the PP, who felt that we had learnt so much stuff over our millennia of being humans. I was pointing out that much of our "learning" would be useless without industrialisation. This, by the way, includes antibiotics; it is materially less likely that antibiotics would have proliferated in such a way without industrialisation for the reasons stated in my previous post: industrialisation was the engine that drove many other discoveries by giving us the time, the manpower, the light, the heat and the machinery to discover such things on a large scale.
Also, I suspect you are wrong about the impact of antibiotics, at least prior to 1950 because it was the case that global infant mortality had already dropped significantly by 1950 - from 1 in 2 to 27% (see links in my PP): nearly halved. It is unlikely that much of that was due to antibiotics. While Fleming discovered penicillin in 1928 it was unstable and unable to be used in a human context. It wasn't until 1939 that a team at Oxford University started working on producing a stable form that could be used as medicine. It wasn't until 1942 that it could be produced reliably and a further two years for its production to be scaled.
I suspect that much of the pre-1950s drop would have been due to the increased understanding of the importance of hygiene, especially in relation to the vulnerable (the very young and the very old). This was made significantly easier on large scale by mechanisation, heated water, better sewerage. All things dependent on the industrial revolution for improvement on a large scale.
Finally, I've found this extract on the history of penicillin from www.acs.org/education/whatischemistry/landmarks/flemingpenicillin.html:
"Pharmaceutical and chemical companies played an especially important role in solving the problems inherent in scaling up submerged fermentation from a pilot plant to a manufacturing scale. As the scale of production increased, the scientists at Merck, Pfizer, Squibb and other companies faced new engineering challenges. Pfizer's John L. Smith captured the complexity and uncertainty facing these companies during the scale-up process: "The mold is as temperamental as an opera singer, the yields are low, the isolation is difficult, the extraction is murder, the purification invites disaster, and the assay is unsatisfactory."
Because penicillin needs air to grow, aerating the fermentation mixture in deep tanks presented a problem. When corn steep liquor was used as the culture medium, bubbling sterile air through the mixture caused severe foaming. Squibb solved this problem by introducing glyceryl monoricinolate as an anti-foaming agent. Submerged fermentation also required the design of new cooling systems for the vats and new mixing technology to stir the penicillin mash efficiently.
Lilly was particularly successful in making the mold synthesize new types of penicillin by feeding precursors of different structure. Once the fermentation was complete, recovery was also difficult; as much as two-thirds of the penicillin present could be lost during purification because of its instability and heat sensitivity. Extraction was done at low temperatures. Methods of freeze-drying under vacuum eventually gave the best results in purifying the penicillin to a stable, sterile, and usable final form.
The steps of fermentation, recovery and purification and packaging quickly yielded to the cooperative efforts of the chemical scientists and engineers working on pilot production of penicillin. On March 1, 1944, Pfizer opened the first commercial plant for large-scale production of penicillin by submerged culture in Brooklyn, New York."
The emboldened portions are my emphasis. Without industrialisation and industrial processes penicillin would never have been available to the masses; it might have become an expensive luxury for the lucky few. In short:
- it required cooling systems; impossible without widely available electricity;
- ditto automated mixing;
- ditto extraction at low temperatures;
- creating the vacuum for to freeze-dry ditto
So, in short, while penicillin may well have been discovered without industrialisation, it is unlikely that it would have played any significant part in reducing infant mortality after 1944 if it had not been for mechanisation and electrification made available by fossil fuels and the industrial revolution. At best, it might have been a privilege of the wealthy.