NATURAL SCIENCE IN THE NINETEENTH CENTURY 377 



simple and luminous style in which his books and papers were written. 



Mathews. 



In England and America the newer physiology made but scant 

 progress until Foster published (in 1876) in England an epoch- 

 making treatise embodying in a fascinating form the methods 

 and results of continental physiology. 



PATHOLOGY BEFORE PASTEUR. Before the nineteenth cen- 

 tury disease was regarded as an inscrutable mystery. Epidemics, 

 plagues, and pestilences came and went, without apparent rea- 

 son. The most fatal and therefore most famous of these was the 

 Black Death of the fourteenth century. Others had been the 

 Plague of Athens, the Sweating Sickness, the Dancing Mania, and 

 Leprosy. One of the worst and commonest was Scurvy, which 

 attacked chiefly sailors, soldiers, prisoners and the poor. 



Attempts to explain disease were manifold. Primitive man 

 naturally attributed it to the power of evil spirits (daemons or 

 devils) and sought prevention and cure in exorcism and the casting 

 out of devils. Hippocrates looked for the sources of disease in 

 abnormal mixtures of four great juices or "humors" of the body, 



blood, yellow bile, phlegm, and black bile ; and his theory had 

 the merit of being based upon natural rather than supernatural 

 ideas, for which reason probably it survived until the time of 

 Sydenham in the seventeenth century. But the theory of Hip- 

 pocrates failed to account for epidemics, for which the cause had 

 to be sought in meteorological disturbances, such as storms, or in 

 astronomical phenomena, such as comets or eclipses, or in unusual 

 terrestrial happenings, such as earthquakes, volcanic eruptions, 

 the flight of birds, the appearance of insects, vermin and what not. 

 With the increase of knowledge in the sixteenth and seventeenth 

 centuries ideas of this primitive kind no longer sufficed, and 

 Sydenham urged that disease must have an independent material 

 basis, a materies morbi. Not much progress was made, how- 

 ever, even by Sydenham, and the eighteenth century left behind 

 it no important contributions to the theory of disease, the work 

 of Hahnemann, for example, bearing upon therapeutics rather 

 than pathology. 



