40 GASTRIC JUICE. 



duces symptoms of choking when injected into the veins : filtered 

 saliva (which has been freed from epithelium, and other morpho- 

 logical substances which might obstruct the capillaries of the lesser 

 circulation) may be injected with perfect impunity. The saliva 

 collected during smoking contains empyreumatic substances, 

 which give rise to symptoms of narcosis when the fluid is injected 

 into the stomach or veins. Hertwig* has shown, by numerous 

 experiments, that even the saliva of mad dogs, when inserted into 

 the stomachs of other animals, or when they are inoculated with 

 it, is unable to produce hydrophobia. 



GASTRIC JUICE. 



The fluid which accumulates in the stomach after the ingestion 

 of food, is in its pure state perfectly clear and transparent, almost 

 entirely devoid of colour, having at most but a very faint yellow 

 tint ; it has a very faint, peculiar odour, and a scarcely perceptible 

 saline-acid taste, and is a little heavier than water ; only a few 

 morphological elements can be perceived in it ; and these consist 

 partly of unchanged cells of the gastric glands, partly of the nuclei 

 of these cells, and partly of fine molecular matter, which is pro- 

 duced by the disintegration of these elements. Its reaction is 

 very acid ; it is not rendered turbid by boiling ; when neutralized 

 with alkalies a slight turbidity may sometimes be remarked. The 

 gastric juice is distinguished from most other animal fluids by the 

 circumstance that it remains for a very long time undecomposed, 

 and that even when a fungous growth (mould) has appeared, it 

 always still retains its most essential character, namely, its digestive 

 power. 



The best method of obtaining gastric juice in a state of the 

 greatest possible purity, is to feed dogs, in whom gastric fistulae 

 have been artificially formed, with bones which they can readily 

 break to pieces ; in the course of from 5 to 10 minutes to open the 

 outer closed extremity of the fistula ; and by means of a funnel 

 and catheter to collect the escaping juice, and to separate it by 

 filtration from flocculi of mucus, and any fragments of food that may 

 be present. It is, however, an objection that a considerable 



* Beitrage zur nahern Kenntniss der Wutlikrankheit. Berlin, 1829, S. 156. 



