AGGLUTINATING ACTION OF SERUM. 



Tlie property of blood serum of given diseases, of causing ag- 

 glutination of the microbe which causes the disease in question, 

 is a remarkable quality now largely availed of for diagnostic pur- 

 poses. The Widal test may be applied by diluting the suspected 

 blood I : ID in a Thoma's hsematocytometer and adding to this on 

 a glass slide a few drops of an actively motile culture of the ba- 

 cillus typhosus, when the microbes promptly cease their move- 

 ments and precipitate in non motile clumps, the liquid becoming 

 clear. It is found that even the dead bacillus, killed by heat, 

 agglutinates and clumps in the same way. This test has been 

 most successfully applied by Gilruth in the diagnosis of hog 

 cholera and has contributed largely to the stamping out of that 

 disease by the segregation of the infected from the non-infected. 



CORPUSCULAR THROMBI FROM SERUM POISONING. 



Flexner has shown that some cases of so-called coagula which 

 occur in the heart in experimental ether and alien serum poison- 

 ing, are not true clots, but masses of agglutinated red globules. 

 Experiment shows that a direct relation exists between extensive 

 blood destruction and agglutination thrombosis, and that such 

 agglutinations in blood-vessels and in vitro are one. In many 

 cases the principles, in animal serums, which cause agglutination 

 or retard it, have much influence on haemorrhage, and the de- 

 struction of tissues, as seen in bites of venomous insects, snakes, 

 etc., and knowledge is rapidly advancing along those lines. 



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