Forty Billion Enemies, 1941

This 1941 General Motors film, Forty Billion Enemies, highlights refrigeration’s fight against bacteria, whose rapid multiplication—hinted at by the title—is curbed by cold. In Kodachrome or black-and-white with sound, a professor lectures in a classroom, joined by shots of trains and trucks speeding food across highways. It links mechanical cooling and swift transport to better health, details temperature’s role in preventing spoilage, and offers practical tips on buying and maintaining a refrigerator, all in a pre-WWII push for modern living.