28 SALIVA. 



6'27 grammes, while during the same period O92 of a gramme 

 were discharged by the fistula ; moreover Mitscherlich never 

 determined the quantity of the parotid secretion, except under 

 definite relations and in given times. Now if we assume that the 

 above ratio of the parotid secretion to the secretion of the other 

 salivary organs is constant, which, however, is more than doubtful, 

 we may calculate the quantity of saliva which will be secreted in a 

 definite time, or under definite physiological relations. Under 

 ordinary circumstances (that is to say, on the common hospital 

 diet) Mitscherlich found that the quantity of the parotid saliva in 

 24 hours varied from 46*3 to 74'8 grammes. Assuming the above 

 ratio of the parotid secretion to that of the other sources of the 

 saliva to be constant, the whole amount of saliva from the six 

 salivary glands and the buccal mucous membrane, would amount 

 on an average to 473 grammes in 24 hours. Burdach* calculates, 

 from Mitscherlich's data, that the saliva secreted by an adult in 

 24 hours amounts to 10 (German) ounces (= 255 grammes). 

 Valentin f assumes the quantity at from 216*4 to 316*3 grammes; 

 Donne J fixes the quantity at 390 grammes, and Thomson at 

 only [3216 grains or] 210 grammes. 



Jacubowitsch has determined in dogs the quantities of saliva 

 which he could collect from each set of salivary glands in an 

 hour; from the tsvo parotids he obtained 49'2 grammes, from the 

 submaxillary glands 38*83 grammes, and from the orbital and sub- 

 lingual glands, and the bnccal mucous membrane, 24'84 grammes. 

 We can draw no conclusions from these data, regarding the quantity 

 of saliva secreted in a normal state in a definite time ; for, indepen- 

 dently of the circumstance that nothing is stated regarding the 

 size or the weight of the dog, we know from his numerical state- 

 ments, that Jacubowitsch employed dogs of various sizes in his 

 experiments, so that the fluid was collected under such peculiar 

 conditions, that a comparison of it with the quantity of the 

 secretion in the normal state is impossible. Jacubowitsch, however, 

 arrived at the interesting result, that to whatever extent the 

 quantities, of the saliva secreted by the different organs may vary, 

 the solid constituents both the organic and the inorganic sub- 

 stances amount to very nearly the same from all three of the 

 sources ; thus, in the quantities above given of parotid, sub- 



* Physiol. Bd. 1, S. 277 ff. 



t Physiol. d. Menschen. 1844. Bd. 1,8. 626. 



* L'Institut, No. 158, p. 59. 



Animal Chemistry. Lond. 1843, p. 571. 



