STARCH, ITS VARIETIES AND CHANGES. 
251 
cyanide of potassium; its solid matter amounted to T2 per 
cent . That of the dog left 2*51 per cent . of solid matter, but 
yielded very slight traces of sulpho-cyanogen. The saliva 
of the horse afforded S'5 per cent, of solid residue, and depo¬ 
sited carbonate and phosphate of lime. According to 
Schultz and Simon, the saliva of the horse contains a notable 
quantity of caseine . Simon found it composed as follows : 
Water ...... 
. 982-0 
Tatty matter, including cholesterine 
o-i 
Ptyaline and extractive matter 
. . 4 -4 
Caseine. 
5-4 
Albumine ..... 
0 6 
Extractive matter and salts 
7' 2 
Loss. 
3 
10000 
Bernard dried some shreds of the mucous membrane of a 
horse’s mouth, and found that even in a desiccated state they 
had the property of converting moistened starch into sugar. 
His conclusions as to the action of saliva on the food are : 
1st. That saliva mixed with buccal mucus has the property 
of converting starch into sugar at the ordinary temperature of 
the body. This was proved with saliva from man, the horse, 
and dog. 
2d. That pure saliva taken from the parotid and sub¬ 
maxillary ducts of the dog will not of itself produce this 
change. 
3d. That the transforming power of the mixed saliva is 
due to its admixture with buccal mucus. 
4th. That in the living body, this power would be neutral- 
izedby theaction ofthegastric juice ; and hencethatthe chemical 
uses of saliva are slight, but its physical advantages are very 
great, by its moistening the food: the evil resulting from the 
absence of this is seen in animals that do not masticate freely. 
By some chemico-physiologists the peculiarity of the 
saliva depends upon the presence of sulpho-cyanogen ; and 
they consider that when its salt is in excess in this secretion, 
it imparts to it poisonous properties. 
In the stomach this change of farina is stayed, from the 
acid nature of the gastric juice; but should any escape into 
the duodenum unacted upon, the pancreatic fluid perfects 
the transformation, which also has another use in the system— 
that of forming an emulsion with fat. 
We must however stop, the article having already exceeded 
our prescribed limits. 
The physiologist knows that starch, as food, is placed among 
