Thombocytes 



499 



mary of the effects of different agents upon the thrombocytes 

 (platelets) in pigeons. 



For differentiation, the modified Nocht stain described by 

 Hastings 1 was used and for counting, a modification of the cresyl 

 violet stain of Buckman and Hallisey. 2 All agents were injected 

 intravenously at body temperature into the wing veins and blood 

 was obtained from superficial veins of the legs. 



The following agents, which cause anaphylactoid symptoms in 

 guinea pigs, pulmonary emboli and thrombi, and hemagglutina- 

 tion in vitro, produced increases in number and clumping of 

 thrombocytes in pigeons ; peptone, agar-sol gel, toxified agar, Con- 

 go red, collargol, charcoal, kaolin, colloidal iron, colloidal arsenic, 

 50 per. cent, acetic acid and 6 per cent, acacia. Histamin, tan- 

 nin and arsphenamin (in small dosage) produced doubtful or no 

 changes in the thrombocytes, but sections of lungs and livers 

 showed marked clumping of erythrocytes from these agents. 



Histological examinations of the lungs, liver, spleen and kid- 

 neys of all animals showed congestion and thrombosis after the 

 majority of the agents that were injected. In a few cases marked 

 hemorrhages w r ere found. The majority of these agents caused 

 definite symptoms, ranging from shivering, crouching, and in- 

 crease in respiration to death. 



On the other hand, the withdrawal of blood alone, and the 

 injection of 0.85 per cent, sodium chloride (as control) pro- 

 duced no symptoms and no demonstrable changes in the throm- 

 bocytes; and histologically, the changes were slight or absent. 



245 (2205) 



The inorganic constituents of human saliva. 



By GUY W. CLARK and G. S. SHELL. 



[From the Department of Biochemistry and Pharmacology, 

 University of California, Berkeley, Calif.] 



There is a growing opinion that many of the pathological con- 

 ditions of the oral cavity (caries, pyorrhea, etc.) are the result 

 of faulty diets. The acceptance of this assumption makes it nec- 



1 Johns Hopkins Hospital Bull., 1904, 122. 



2 J. Am. Med. Assoc., 1921, lxxvi, 427. 



