how does putting kids with other chicken pox kids give them chickenpox if it is wrong ?

why did the invention of soap change history ?

i understand and maybe there is truth to both. we do have parts of old viruses in our dna.

just in 1860 they were chopping legs off in the civil war with no anesthesia and little sanitation. we are really not much more advanced except we can see things easier, and sanitation. but it seems like things have adapted to most of our stuff.