TEACHING OF PHYSIOLOGY AND PUBLIC HEALTH. 31 



to this day to that effect. The remains of the aqueducts 

 around Rome show on what a stupendous scale the city was 

 furnished -with pure drinking water. On the other hand, 

 history plainly tells us that the wanton violation of physio- 

 logical laws by the pleasure-loving Romans of later days, 

 together with the epidemics that repeatedly devastated the 

 Imperial city, had much to do with the decline and fall of 

 the empire. 



It is, however, in the Middle Ages that we see the most 

 flagrant violations of the laws of health. The clothing of 

 the people was made almost entirely of wool, and little 

 suited to the varying temperatures. The dwelling houses 

 were of the rudest construction; and clean floors were 

 unknown. New straw was placed from time to time upon 

 the floors of dwellings to cover up the filth that had accu- 

 mulated there. A writer of this period states that when- 

 ever he went into a house of this kind he was immediately 

 seized with a fever. Strong ale and sour wine, usually 

 drunk to excess, were prolific sources of disease, and 

 highly seasoned and salted meats formed the substance of 

 the daily diet. Streets were unpaved, and almost to the 

 close of the Middle Ages the man who would have started 

 to walk down the streets of Paris itself on a rainy day 

 would have stepped into mud up to his ankles. Sewers 

 were unknown, and the filth and garbage were turned over 

 to the slow process of decomposition in their very midst. 



When one remembers that there was constant fighting, 

 that people were crowded in walled fortresses and towns 

 without pure air, and finally adds that the country was 

 filled with murderers, marauders and thieves, with frequent 

 famines to augment this class, one can appreciate what was 

 meant by Darwin's notion of the " survival of the fittest." 

 Only the strongest and heartiest survived ; the weak went 

 to the wall. It was an illustration of Darwin's law with 

 barbarous reality. But it gave to the modern age a picked 

 race of stronger and heartier people. One is not surprised 

 that under such conditions epidemics were plentiful and 



