HEMOLYTIC SERA AND THEIR ANTITOXINS. 195 



rapidly an equal or even a slightly superior volume of rabbit blood. 

 For example 0.5 of a cubic centimeter of blood added to 0.4 of a 

 cubic centimeter of serum gives a complete destruction of all the 

 corpuscles in about an hour. 



In this latter experiment we have supposed an instance in which 

 the amount of blood (0.5 of a cubic centimeter) was added all at once 

 to the 0.4 of a cubic centimeter of serum. But the blood may also 

 be added in fractions ; we may add to the 0.4 of a cubic centimeter of 

 hemotoxin, first 0.2 of a cubic centimeter of blood, and later 0.1 of a 

 cubic centimeter and, after an hour or two, a third 0.2 of a cubic 

 centimeter. In other words, we determine whether a given amount 

 of serum is uniformly able to destroy the same number of corpuscles 

 whether they be added all at once or in divided doses. As a matter 

 of fact it is found that the dissolving property of serum is rapidly 

 exhausted if the blood is introduced gradually in small amounts, 

 particularly when the time intervals between the doses are some- 

 what prolonged. We find that 0.4 of a cubic centimeter of fresh 

 hemolytic serum — an amount capable of destroying completely 

 at least 0.5 of a cubic centimeter of blood when added at once — dis- 

 solves no more than 0.2 of a cubic centimeter of blood if the cor- 

 puscles are added to the serum in divided doses. The first doses 

 introduced are well dissolved until the total amount of blood added 

 is about 0.2 of a cubic centimeter, but subsequently added corpuscles 

 remain intact. At least twice as much blood then may be dis- 

 solved when added to serum all at once as when added in divided 

 doses. It is evident that in the latter instance the first corpuscles 

 added become in some manner supersaturated with the active sub- 

 stance and exhaust the fluid so that it becomes inactive for other 

 corpuscles. In other words, the first corpuscles absorb more active 

 substances than is necessary for their dissolution. 



This seems to us to favor the conception that the absorption of 

 active principles by the corpuscles should be compared to a dyeing 

 phenomenon. In such phenomena, as we know, the substances to 

 be dyed absorb varying amounts of the dye under conditions that 

 are quite similar to those just outlined for corpuscles. 



If we pour 10 c.c. of a diluted rather pale solution of methyl violet 

 in a crystallizing dish, a piece of filter paper placed in it becomes 

 colored. It soon takes on a uniform pale tint, while the fluid, as it 



