176 DIGESTION. 



gar. 1 Bernard obtained the pure secretions from the parotid 

 and from the subm axillary glands in the human subject, by 

 drawing it out of the ducts as they open into the mOuth, 

 with a small syringe with the nozzle arranged so as to 

 fit over the papillae, and demonstrated their action 011 

 starch. 2 This fact, with regard to the parotid, had previ- 

 ously been established in a patient with a fistula into the 

 duct of Steno by Jarjavay and Mialhe, the experiment hav- 

 ing been made at the suggestion of M. Berard. 3 In this case 

 the fluid from the fistula transformed starch into sugar with 

 great facility. Longet afterward showed that a mixture of 

 the secretions of the subrnaxillary and the sublingual glands 

 had the same property. 4 



It is unnecessary, in this connection, to recite the numer- 

 ous experiments on the influence of the saliva of the inferior 

 animals 011 starch ; but it may be stated, as an established 

 and generally accepted fact, that the mixed saliva and the 

 secretion of the different salivary glands, in the human sub- 

 ject, invariably transform cooked starch into sugar with 

 great rapidity in the mouth, and also, at the proper tempera- 

 ture, out of the body. It has been also shown by Mialhe 

 that the starch, though it is converted rapidly into sugar in 

 this process, is first transformed into dextrine. 5 



This point being settled, there arises the important ques- 

 tion whether the action of the saliva be really important in 

 the digestion of starch, or whether this transformation be 

 merely accidental ; for it has been shown that other fluids, 



1 See page 159. 



2 Loc. tit. 



3 BERARD, Cours de Physiologic, Paris, 1849, tome ii., p. 403, note. 



In many cases of salivary fistula, the fluid discharged failed to effect the 

 transformation of starch. In the observations of Prof. Dalton on the parotid 

 saliva taken from the duct by a tube introduced by the mouth, the transforma- 

 tion was complete. (Verbal communication.) 



4 LONGET, Traite de Physiologic, Paris, 1861, tome i., p. 171. 



8 MIALHE, Chimie appliquee d la Physiologie et d la Therapculique, Paris, 

 1856, p. 40, 



