500 APPENDIX. 



saliva takes no very important part in the digestion of the amylacea. 

 Hence its principal use in the animal body must be of a mechani- 

 cal nature. Besides the uses of this nature, mentioned in the text. 

 Bidder and Schmidt believes that one of the main objects of the 

 salivary secretion is its co-operation in the perpetual interchange 

 of the watery fluids within the living organism. 



(4) Addition to p, 41, line 15. Schmidt, who analysed speci- 

 mens of gastric juice free from lactic acid, found that in nine 

 analyses of the gastric juice (not mixed with saliva) of dogs, the 

 free hydrochloric acid varied from 0*245 to 0*423$, the mean being 

 0*335$; in gastric juice containing saliva, he obtained in three 

 analyses from 0*1708 to 0*3353 $, the mean being 0*2337$; while 

 the gastric juice from the fourth stomach of the sheep yielded as 

 the mean of two analyses 0*1234$. The gastric juice of the sheep 

 always contained a little lactic acid, which, however, was apparently 

 not secreted by the glands in the walls of the stomach, but formed 

 by fermentation from starch. 



(5) Addition to p. 45, line 4. Schmidt, moreover, found that 

 chloride of ammonium was constantly present in the gastric juice; 

 its quantity varied in the pure f gastric juice of the dog from 0*0372 

 to 0*065 % (the mean being 0*047^), and in the gastric juice mixed 

 with saliva from 0*0276 to 0*084$, while in the gastric juice of the 

 sheep it averaged 0*0475$. The gastric juice (free from saliva) of 

 the dog contains on an average 0*4256$ of fixed chlorides, while 

 that which is mixed with the saliva contains 0*588$, the addition of 

 the saliva to the gastric juice inducing an augmentation of the 

 chlorides of sodium and calcium ; of the latter Schmidt found only 

 0*0624$ in pure gastric juire, while the quantity amounted to 

 0*1661$ in the mixed fluid. The gastric juice (containing saliva) of 

 the sheep contains on an average 0*6$ of fixed chlorides. 



(6) Addition to p. 46, line 5. With regard to the ferment of 

 the gastric juice, Schmidt obtained it by neutralising the fluid 

 with lime-water, evaporating to the consistence of oil, and precipi- 

 tating with anhydrous alcohol ; this precipitate was then dissolved 

 in water,and thrown down with bichloride of mercury; in the organic 

 matter of this mercury-compound Schmidt found 53*9$ of carbon, 

 6*7$ of hydrogen, and 17*8$ of nitrogen. 



The mean amount of the organic matters both in pure and in 



