HJEMOLYSINS AND ALLIED BODIES 437 



Similarly, if frog's blood be injected into a rabbit, the serum 

 of the latter will lake frog's erythrocytes ; although, in this case, 

 the specific nature of the hsemolysin is not so definite, for the 

 corpuscles of the salamander, triton, the toad, &c., are also laked 

 by this serum. 



It may, therefore, be stated as a law that the blood serum of an 

 animal of a species A, when that animal is repeatedly treated 

 with the blood of a species B, acquires the property of causing 

 hcemolysis of the erythrocytes of species B, and to a less extent 

 of other species of the same genus as B. Not only intraperitoneal, 

 but also subcutaneous or intravenous injection of the blood, will 

 lead to the production of the hsemolysin. Hsemolysins may also be 

 produced by feeding an animal with the blood of another species. 



This laking can be most conveniently studied in a test-tube, 

 the erythrocytes to be tested (of B) being first of all washed free 

 of adherent serum by shaking then with isotonic salt solution and 

 centrifugalising until the washings no longer give a proteid 

 reaction, then suspending in 20 parts of isotonic saline. Into each 

 of a series of narrow test-tubes of about 5 c.c. capacity is placed 

 1 c.c. of the corpuscular suspension. Different amounts of the 

 serum (1 c.c., -5 c.c., -25 c.c., ! c.c., -05 c.c., *025 c.c., and so on) 

 to be tested are then mixed with the erythrocytes, the fluid in each 

 test-tube is brought up to a definite amount say 2 c.c. the test- 

 tubes are inverted several times so as to mix their contents, and 

 are then placed in the incubator for a few hours. Laking is 

 indicated by the salt solution becoming red and transparent on 

 account of the haemoglobin dissolving in it. 



Haemolysis may also occur in the blood-vessels on the injec- 

 tion of a specific heemolysin into an animal. The liberated 

 haemoglobin in such cases appears in the urine, and various other 

 symptoms are produced, being usually followed by the death of the 

 animal. This fact was discovered by Belfanti and Carbone. 

 Before Bordet's article appeared these authors injected rabbit's 

 blood into horses, and found that the horses' serum, when injected 

 into a rabbit, acted as a violent poison, producing hsemoglobinuria 

 and being followed by death. 



Bordet further discovered that heating the haemolytic serum 

 of a guinea-pig to 55 C. for half-an-hour deprived it of its 

 hsemolytic power towards rabbit's erythrocytes. It had become 

 inactivated by heating; therefore something necessary for haemolysis 



