Die Parasiten der Infectionskrankheiten. 37 
added a fact of great interest and importance in progressive phy- 
siological knowledge, but this discovery was from the first associa- 
ted with pathological conditions, the later studies and better un- 
derstanding of which have led to comprehensive, exact and 
highly important practical conclusions in regard to symptoms and 
pathological changes which had hitherto been most important, but 
at the same time most difficult, if not impossible, to understand. 
We refer to the mechanical and pathological conditions which in 
this disease manifestly produce cholaemia, and to certain demon- 
strations here alluded to concerning the morbid condition and 
destructive effects of the bile as witnessed in this disease. The 
studies which Frerichs and other high anthorities have given 
to this class of facts without such means of demonstrations, have 
been corroborated and placed upon a more definite practical foo- 
ting by the results of these researches. 
3) The demonstration of consecutive pathological changes, and 
of their relations to the fatal result. No other, pestilential or febrile 
disease, whether epidemic or epizootic, has furnished to medical ob- 
servers such a complete and consecutive series of demonstrations 
of the steps by which disease progresses from its incubative be- 
sinnings to perilous and destructive changes in tissues and proxi- 
mate elements to obvious symptoms and exclusiye phenomena, un- 
til death terminates the pathological record of events. Considered 
with reference to the progress of medical knowledge and hygienic 
measures, in regard to epizootics and enzootics, as well as in re- 
gard to epidemics and certain of the spreading pestilences that 
depend upon contingent circumstances that hitherto have not been 
well demonstrated, the results reached in these investigations may 
justly be regarded as in the highest degree encouraging and in- 
structive. The successful study of the essential morbid changes 
that occur during the progress of this disease in the blood, the 
bile, the liver, the most vascular and constricted portion of the 
stomach and the spleen, and lastly, the explosive phenomena, the 
destruction of the blood corpuscles, the waste of blood ele- 
ments of the kidneys, and the morbid alterations that occur in 
those organs, and in conclusion, the phenomena and circumstan- 
ces of death, together with that impressive and truth-telling sig- 
net which the damaged and broken blood corpuscles leave in the 
tissues, cavities and fluids into which the spoiled and stagnant 
blood has oozed and left crystals of haematoidine, singly, and in 
