Hydrochloric Rabbit Blood Serum in Dogs. 147 



finds its way into the blood stream. In such case it would natu- 

 rally act as an auto-intoxicant and would be one of the factors in 

 the death of the animal. 



A number of years ago one of us attempted on this assumption 

 to isolate choline from the blood of a hydrophobic rabbit. The 

 amount of blood taken was not more than 30 c.c. and the result 

 was negative. 1 We have repeated this attempt on larger quanti- 

 ties of blood. The blood of three rabbits inoculated 7 and 8 days 

 previously with the fixed virus was run into absolute alcohol. 

 The alcoholic extract was filtered off and evaporated to dryness at 

 a low temperature. Platinic chloride was added in the manner 

 recommended for the production of choline platinic chloride crys- 

 tals. The precipitate obtained was examined under the micro- 

 scope. It was made up of six-sided yellow crystals, a large part 

 of which were in plate form. There were not sufficient crystals to 

 determine the per cent, of platinum. 



Thus far it would appear that in hydrophobia, as in certain 

 other diseases, where there is destruction of nerve tissue, choline 

 is one of the split products. A number of other experiments are 

 being carried out to check and amplify these results. 



Last year Dr. Poor, of the Research Laboratory, and one of us 

 attempted to protect rabbits from hydrophobia by means of in- 

 jections of atropine, which antagonizes choline on the assumption 

 that choline was present in the blood of rabbits with hydrophobia. 2 

 The results were unsuccessful but have been undertaken again 

 under a different system. The results of this second attempt will 

 be published later. 3 



J J. P. Atkinson, in 1903, unpublished. 

 2 J. P. Atkinson, unpublished. 



'Since these results were presented the following experiment was made: The 

 blood of a normal rabbit, which had been 72 hours previously injected subdurally 

 with an emulsion of normal brain substance was run directly into absolute alcohol 

 and the rabbit immediately autopsied. The autopsy showed signs of considerable 

 necrosis and inflammation at the point of injection. The filtered alcoholic extract 

 of this rabbit's blood was evaporated to dryness at a low temperature and mixed with 

 physiological salt solution. This mixture was injected into the femoral vein of a 

 dog and the arterial pressure as taken with the mercurial manometer from the 

 carotid artery showed a marked depression. Five cubic centimeters of the clear 

 defibrinated serum of this blood also caused a marked depression. 



