540 



Mr. E. C. Hort. 



[June 2, 



conditions. The results given by both methods in determining the vakies of 

 the serums after injection of water were parallel and mutually confirmatory. 

 The results of the viscosity method, slightly modified by myself, being the 

 simplest, are given below. To 10 c.c. of a 40-per-cent. mixture of casein 

 and water is added 0-25 c.c. of the serum of the antitryptic value of which 

 estimation is desired. At a fixed time 1 c.c. of a 1-per-cent. filtered fresh 

 solution of trypsin in water is added to the casein mixture, and digestion 

 allowed to proceed at a constant temperature, in this case 19° C. Before 

 adding the trypsin solution, observations are taken with a stop-watch to 

 determine the length of time occupied by the discharge from the viscosimeter 

 of the contents of the bulb between two marked points. After addition of 

 the trypsin solution, repeated observations are taken at intervals in exactly 

 the same way. All the serum-casein-trypsin mixtures are then put through 

 the viscosimeter at the same intervals of time, and in this way comparable 

 results are obtained. 



Experiment. 





Injected 



Injected 



Control 



Control 





rabbit before 



rabbit after 



rabbit before 



rabbit after 





lirst 



last 



time of first 



time of last 





injection. 



injection. 



injection. 



injection. 



Discliarge time before addition of 



2.49 



2. 40 ! 



2.49i 



2. 49 



trypsin 











First roading,lC minutes after addition 



2.12 



2. 12^ 



2. 12 



2. 11? 



of trypsin 









Second reading, 4') minutes after 



2.0 



2. H 



2. 01; 



1. 59 i 



addition of trypsin 











Third reading, 110 miniites after 



1. 50i 



1.514 



1.50;- 



1.50 



addition of trypsin 







From these figures it is clear that, whereas, in the case of the control, the 

 serum from the second bleeding showed, if anything, a somewhat lower anti- 

 tryptic value than the serum from the first bleeding, the serum of the injected 

 animal showed after injection a slight but unmistakable rise in antitryptic 

 values compared with the reading before injection, in si)ite of the smallness 

 of tlie injection. The weight of the animal was almost 5 lbs. 



(b) Gidnea-piffs. 



A guinea-pig, weighing 442 grammes, received subcutaneously an injection of 

 5 c.c. of water. This was followed in three hours l)y a rise of temperature, 

 the height of which was intensified by a previous injection of the same bulk 

 16 dayn previously, and l)y a thiid in j(!(;ti<m of the same bulk 18 days previously. 

 The final injection was followed by a fall of weiglit from 442 grammes to 



