PROGRESS OE VETERINARY SCIENCE AND ART. 205 
as characters in common the properties of being unaltered by 
heat, of passing off with watery vapour during distillation, 
and of separating hydrochloric acid from the chlorides. In 
following out the comparison between these two acids, we 
have found that the acid of the gastric juice has all . the 
properties which Pelouze ascribes to lactic acid ; these two 
acids form alike salts soluble in water with lime, baryta, zinc, 
and copper ; a salt of copper which forms with lime a 
soluble double salt, the colour of which is more intense than 
that of the simple salt ; a salt of lime soluble in alcohol and 
precipitated by ether from its alcoholic solution.” 
The free fats are not acted upon by the gastric juice; 
but the vesicles and connecting fibres of fatty tissue are 
dissolved by it. Starchy principles suffer disaggregation ; 
but are not altered chemically. 
By prolonged contact, cane or beet-root sugar may assume 
the form of grape sugar ; this retrograde change occurs 
perhaps in virtue of the acidity of the gastric juice. Grape 
sugar may become converted into lactic acid by similar 
prolonged contact. 
Gastric juice has a very evident action on the nitrogenized 
elements of food. Flesh is converted into a grayish mass, 
chyme. This only depends on solution of the connecting 
areolar tissue, and is more rapid with cooked than raw meat. 
The same occurs with glandular or nervous tissue. 
There are many complex elements on which the gastric 
juice exerts a peculiar action, such as on coagulated milk and 
boiled albumen, both of which it redissolves, or on bone, 
which it digests ; that is to say, the gastric juice dissolves the 
albuminoid constituents of bone, so that the earthy matter is 
set free, and most of the latter is passed on as excrementitial. 
Thus the gastric juice acts quite differently to simple acidu- 
lated water, which dissolves the calcareous portion and leaves 
intact the animal basis of osseous texture. 
The epidermic tissues of animals and vegetables resist the 
action of the gastric secretion. 
In the foregoing operations the gastric juice is effective in 
virtue of its acid and organic principle ; but it may act simply 
as a dilute acid, such as on iron filings and on certain salts. 
Thus the cyanides are quickly decomposed on reaching the 
stomach from the hydrocyanic acid being set free by the acid 
of the gastric juice, which accounts for the rapidity with which 
the symptoms of poisoning manifest themselves. If, then, 
we wish a substance to be specially acted upon as by an acid 
it must be introduced into the stomach during active digestion, 
and persons have said that it should not be combined with 
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