CONTRIBUTIONS TO THE THEORY OF LYSIN ACTION. 3 



acts, though to a less degree, on the blood-cells of rats and mice. 

 The active guinea-pig serum injected into the ear- vein of a rabbit 

 is highly toxic to that animal. 



The analogy existing between these phenomena and those of 

 bacteriolysis is, as emphasized by Bordet, a very close one. This 

 will be clear to the reader. Very likely, therefore, the mechanism 

 of haemolysis and that of bacteriolysis are very similar. The study 

 of haemolysis thus gains considerable theoretical significance. 



Being so fortunate as to have at our disposal a considerable amount 

 of appropriate serum, we have used this in order to gain a deeper in- 

 sight into the nature of haemolysis. This serum was derived from a 

 goat which during eight months had been subcutaneously injected in 

 somewhat irregular fashion with sheep serum rich in blood-corpuscles. 

 The experiments were therefore made with sheep blood in the form 

 of a 5% mixture of the defibrinated blood in 0.85% salt solution. 

 By means of this great dilution certain sources of error arising from 

 the constituents of the serum are avoided. These had manifested 

 themselves in Bordet's experiments. 



The serum of our goat rapidly dissolves sheep blood-cells in vitro. 

 The degree of action of this serum can be accurately determined as 

 follows: To each 5 cc. of the above-mentioned blood mixture decreas- 

 ing amounts of the goat serum are added. It is then found that 

 at 37 C. the specimens containing from 1.5 cc. to 0.8 cc. serum will 

 become completely laky. After allowing all the specimens to act 

 for two hours in a thermostat they are placed in a refrigerator and 

 allowed to settle. It will then be found that there is a regular 

 decrease in the amount of solution effected until finally the limit 

 is reached in the specimen containing 0.1 cc. of serum. The serum 

 of normal goats (we tried the sera of a number of different animals) 

 is unable even in large amounts to dissolve sheep blood-cells. It 

 is to be remarked that in the use of this immune serum in the amounts 

 mentioned no clumping was ever observed to precede haemolysis, 

 although this phenomenon was carefully looked for. 1 



1 The serum of normal goats in doses of 1.5 cc. and over possesses the prop- 

 erty to agglutinate sheep blood-cells, but this property seems to be subject 

 to great individual and chronologic fluctuations. This agglutination of foreign 

 bloods by certain normal sera, and which probably corresponds to the normal 

 agglutinating action of sera on bacteria, was observed many years ago by 

 Creite (Z. f. rat. Med., Vol. 36) and later was again emphasized by Landois 

 (Die Transfusion des Blutes, 1875). 



