196 VENOMS 
after a contact of two hours or more, 2 c.c. of distilled water be 
added, coagulation is produced just as in saline plasma without 
venom. 
B.— EFFECTS OF VENOM UPON THE RED CORPUSCLES. 
(1) Hæmolysis.—The hemolytic properties of venoms, that is 
to say, their faculty of dissolving the red corpuscles, have been 
the subject of very important researches on the part of a number 
of investigators during the last few years (W. Stephens,’ Flexner 
and Noguchi,’ Calmette,* Phisalix,! Preston Kyes and Hans Sachs,” 
INGE): 
The different venoms are all hemolytic, but in very variable 
doses. It is possible to make a very precise comparative study of 
them from this special point of view by taking as a base for each 
venom, as was done by Noc, the unital dose of 1 nulligramme 
(or one-tenth of a cubic centimetre of a 1 per cent. solution freshly 
prepared and not filtered, the filtration through porcelain retaining 
an appreciable part of the active substance), and noting the time 
strictly necessary for this dose of 1 milligramme to dissolve com- 
pletely, a vitro, 1 c.c. of a 5 per cent. dilution of red corpuscles of 
the horse in physiological saline solution. 
It is very important, before allowing the venom to act on the 
red corpuscles, to first wash the latter by means of several suc- 
cessive centrifugings with 8 per 1,000 physiological saline solution. 
It is also better to choose the corpuscles of the horse in 
preference to those of other species of animals, since they exhibit 
1 Journal of Pathology and Bacteriology, 1899-1900. 
2 Journal of Experimental Medicine, March 17, 1902 ; University of Penn- 
sylvania Medical Bulletin, November, 1902. 
> Comptes rendus de l'Académie des Sciences, June 16, 1902. 
1 Comptes rendus de la Société de Biologie, No. 27, 1902. 
5 Berliner klinische Wochenschrift, Nos, 38, 89, 1902 ; Nos. 2-4, 1908; Nos. 
42-43, 1905. 
6 Annales de UInstitut Pasteur, 1904, p. 387. 
