146 



Scientific Proceedings (39). 



other hand, Bohn states that the rhythm disappears after a time, in 

 laboratory specimens and my failure to observe anything farther 

 indicating a change in phototaxis may be due to the disappear- 

 ance of the rhythm from the animals. Details of the experi- 

 ments are published in another journal. 



93 (503) 



The vaso reaction of hydrophobic rabbit blood serum in dogs. 

 By J. P. Atkinson and C. B. fitzpatrick. 



[From the Chemical and Research Laboratories of the New York 

 Department of Health.] 



In November of last year we injected into the femoral vein of a 

 dog 5 c.c. of the defibrinated centrifuged blood of a rabbit, which 

 had previously been injected subdurally with a fixed seven days' 

 virus of hydrophobia. 



The arterial pressure taken with a mercurial manometer from 

 the carotid artery showed a marked depression. Further trials 

 of the same experiment gave the same results. Since these experi- 

 ments, we have been able to demonstrate that the blood serum of 

 rabbits, which have been infected with hydrophobia 72 and 48 

 hours previously as described, possess this depressor substance, 

 and even in the serum of a rabbit which had been infected only 24 

 hours previous to bleeding, there was a decided indication of a 

 depressor substance. 



If the blood of a rabbit suffering from hydrophobia be run into 

 absolute alcohol and the filtered alcoholic extract be evaporated 

 on the water-bath or in vacuo, there will be found a water-soluble 

 substance which causes a marked arterial depression. We ob- 

 tained this depressor effect in the alcoholic extract also from the 

 blood of the rabbits injected only 48 and 24 hours respectively 

 before the test. 



Choline is a poisonous nitrogenous base derived from the phos- 

 phorized fat of neucleo-protein, in which brain and nerve tissue 

 are very rich. It has been demonstrated that hydrophobia travels 

 along the nerve from the point of injection to the brain. It seems 

 to us quite possible that in the development of the disease neucleo- 

 protein is decomposed ; among its decomposition products choline 



