ItAMtLTON SCIENTIFIC ASSOCIATION. 37 



Bichat (1771-1802) attributed to every bodily tissue its specific 

 vital properties of sensibility and contractility. Alterations in 

 these properties gave rise to disease. 



Rush (Philadelphia — 1 745-1813) regarded disease as due to a 

 morbid excitement induced b}^ irritants acting upon a debilitated 

 body. 



During the nineteenth century we find Schonlein (1793- 1864) 

 stating that disease is an independent entity or parasite sojourning 

 temporarily within the bod5\ Against this entit}' the body finds 

 itself constantly in a state of defence. 



Henle (1809- 1885) regarded disease as a deviation from the 

 normal typical process of life. 



Virchow (1871-190-) defined disease as altered impressions of 

 the vital force either in the body or its fluids. 



The improvement of the microscope now led to fresh discov- 

 eries and new theories. 



Heuter (1873) claimed that all diseases, whether external or 

 internal, depended upon the entrance of fungoid monads into the 

 bod5\ 



I have given this brief introduction on the history- of medicine 

 just to show how near to, and yet how far from, the theories of 

 health and disease as we understand them to-day, tliese early 

 masters were, and while we, at the beginning of the twentieth cen- 

 tury, ascribe a great manj^ diseases to germ causation, we are not 

 quite so sweeping in our assertions as was Heuter in 1873. There 

 are, however, even to-day some who would strive to attribute all 

 pathological conditions to bacterial causes. 



What are these organisms to which so much of human ill, yea, 

 of human welfare, also, is due ? 



Bacteria, germs or microbes are miiuite, unicellular plants, ex- 

 isting in three chief forms, viz. : 



I. The Sphere or Coccus — 1-80000 to 1-8000 inches in 

 diameter. They are non-motile, and some have 

 capsules. Examples are the germs causing erysip- 

 elas, pneumonia and those producing pus. 



