32 STUDIES IN ADVANCED PHYSIOLOGY. 



famines frequent. Thus, in the twelfth century there are 

 recorded fifteen general epidemics; in the thirteenth cen- 

 tury, twenty general epidemics; in the fourteenth century, 

 eight. It was in 1348 that Europe was devastated with the 

 epidemic called " The Black Death," or "The Great Mor- 

 tality." In London, alone, 100,000 people were carried 

 away, and it is estimated that on the continent of Europe 

 not less than one-fourth of the population, that is, more 

 than 25,000,000 of people, fell prey to its ravages. The 

 imagination of to-day fails to picture the horror and black 

 despair of the time. Throughout all this period epidemics 

 were believed to be visitations from an angry God, and 

 there were not missing observations of armies fighting in 

 the air, and other supernatural phenomena which served as 

 warnings and forerunners of these dread times. 



With the middle of the seventeenth century there 

 dawned a better day. Improved methods of agriculture 

 and commerce materially bettered the daily food of the 

 people. The introduction of tea and coffee replaced the 

 baneful effects of strong ale and spirits; and the intro- 

 duction of the potato displaced the highly seasoned meats. 

 Cotton and linen goods were revolutionizing clothing. But 

 possibly the greatest advance of all was the discovery of 

 soap. With the introduction of this now indispensable 

 article the reign of filth and uncleanliness began to weaken. 

 More and more general attempts at municipal cleanliness 

 resulted, and it began to dawn in the minds of men that 

 disease and filth had a causal connection. Men learned for 

 the first time that the prevention of disease might be inves- 

 tigated as a scientific problem. Several remarkable dis- 

 coveries about this time helped materially in the sanitary 

 evolution of civilization at large. One of these was the 

 discovery of Captain Cook that that dread disease, scurvy, 

 might be entirely prevented. This disease had for cen- 

 turies decimated the ranks of soldiers and sailors, and was 

 the especial dread of every ship's crew. The simple 



