INSALIVATED^. 159 



utes. Tliere was no marked difference between them in this 

 respect. 



u While making some similar experiments to the above 

 on a previous patient, in April, 1863, I found that with the 

 canula introduced into Steno's duct, not only was the dis- 

 charge of parotid saliva increased by the mastication of food, 

 but that it ran from the canula very much faster than in a 

 state of rest, whenever the patient smiled, spoke, or moved 

 his lips or cheeks in any way." 



The organic matter of the parotid saliva is coagulable by 

 heat (212 Fahr.), alcohol, and the strong mineral acids. 

 Dalton found, in the human saliva, that it w r as also coagulated 

 by an excess of sulphate of soda ; but Bernard states that in 

 the parotid saliva of the horse, the organic matter will pass 

 through a mixture of sulphate of soda, but is coagulated by 

 sulphate of magnesia. 1 Almost all physiologists agree that 

 this organic matter is not identical in its properties with 

 albumen, nor with the peculiar principle described by 

 Mialhe in the mixed saliva, under the name of animal dias- 

 tase. 2 



A compound of sulpho-cyanogen is now generally ac- 

 knowledged to be a constant constituent of the parotid saliva. 

 This cannot be recognized by the ordinary tests in the fresh 

 saliva taken from the duct of Steno, but in the clear filtered 

 fluid which passes after the precipitation of the organic mat- 

 ter, there is always a distinct red color on the addition of 

 the persulphate of iron. As this reaction is more marked in 

 the mixed saliva, the methods by which the presence of a 

 sulpho-cyanide ^is to be demonstrated will be considered in 

 connection with that fluid. 



In the human subject, the parotid secretion is more abun- 

 dant than that of any other of the salivary glands. The en- 

 tire quantity in the twenty-four hours has not been directly 



1 BERNARD, Lemons de Physiologic Experimental^, Paris, 1856, p. 67. 

 a MIALHE, Chimie appliquee d la Physiologic d d la Therapeutique, Paris, 1856, 

 p. 39. 



