342 CHEMISTR Y OF THE DIGESTIVE FEO CESSES. 
fluid, aided by the presence of free fatty acid in the fat used for the 
experiments. 1 
Paschutin 2 attempted by two different methods to separate the 
diastatic and inverting ferments : — 
1. An infusion of the intestinal mucous membrane -was made by rubbing 
it up with water and powdered glass, and filtering. When this infusion was 
mixed with a solution of collodion, the precipitated collodion brought down 
most of the inverting enzyme, and most of the diastatic enzyme Avas left in 
solution, but only a partial separation could be effected in this manner. 
2. The mucous coat of a piece of intestine was freed from the other coats, 
and then water was filtered through this, under pressure. The fluid which 
filtered through acted energetically on starch, but had no action or only a 
very feeble one on cane-sugar. 
THE CHEMICAL COMPOSITION OF THE DIGESTIVE 
SECRETIONS. 
Saliva. 
The saliva is a mixture in varying proportions of the secretions 
of the different salivary glands. As these secretions differ from 
one another considerably in chemical composition, it will be well 
to consider first the physical and chemical nature of each of them 
in turn, and afterwards that of the fluid which results from their 
admixture. 
Submaxillary saliva.— Submaxillary saliva may be obtained by in- 
serting a fine cannula into the opening of Wharton's duct. In some 
individuals Wharton's duct carries to the mouth the secretion of the 
submaxillary gland only, in others the duct of Bartholin leads into 
Wharton's duct, when the latter conducts the mixed secretion of the 
submaxillary and sublingual glands to the mouth. The tongue should 
be raised, but not too high, the cannula carefully inserted and gently 
pushed into the duct for about an inch. By this procedure the eud of 
the cannula is thrust past the opening of the duct of the sublingual 
gland, in case both glands share a common duct, and so the obtaining of 
submaxillary saliva only is ensured. 3 
Human submaxillary saliva is a clear, watery, mobile fluid, which 
becomes viscid on standing in contact with air, and deposits flocculi. 
It is always alkaline in reaction. On boiling, it becomes cloudy, and 
the cloudiness is increased by the addition of acid. Its specific gravity 
varies between P0026 and T0033, and is lessened by hunger. The 
amount of total solids lies between - 36 and 046 per cent., and is not 
much influenced by food. According to Eckhard, it contains no 
sulphocyanates, while Oehl and Sertoli 4 state that it contains them, 
but in less amount than the secretion of the parotid. Colorimetric 
1 See, however, Schiff, Arch, dc jriiysiol. norm, ct path., Paris, 1S92, tome xxiv. p. 679. 
Scliiff here repeats his earlier statements, that suceus entericus acts both on proteids and 
neutral fats. Prege {Arch. f. d. ges. Physiol., Bonn, 1896, Bd. lxi. S. 3f>9) has recently 
obtained succus entericus from a Vella fistula in the sheep, and determined that it has no 
action on proteids or neutral fats. 
2 A rclt. f. Anat. u. PhysioL, Leipzig, 187], S. 305. 
3 Eckhard, Jahresb. u. d. Fortsch>\ d. ges'. Med., Erlangen, 1862, Bd. i. S. 126; cited 
from Maly, Hermann's " Handbuch," Bd. v. (2), S. 17. 
4 Oehl, Jahresb. u. d. Fortschr. d. ges. Med., Erlangen, 1865, Bd. i. S. 120; Sertoli, 
ibid., 124. 
