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SALIVA. 453
have been investigated by PflUgeb.1
He found 0.5-0.8 per cent oxygen,
0.9-1 per cent nitrogen, and 64.73-85.13 per cent carbon dioxide
—
all results calculated at 0° C. and 760 mm. pressure. The greater part
of the carbon dioxide was chemically combined.
The two kinds of submaxillary secretion just named have not thus
far been separately studied in man. The secretion may be excited by an
emotion, by mastication, and by irritating the mucous membrane of the
mouth, especially with acid-tasting substances. The submaxillary saliva
in man is ordinarily clear, rather thin, a little ropy, and froths easily.
Its reaction is alkaline toward litmus. The specific gravity is 1.002-
1.003, and it contains 3.6-4.5 p. m. solids. 2
As organic constituents
are found mucin, traces of protein and diastatic enzyme, which latter is
absent in several species of animals. The inorganic bodies are alkali
chlorides, sodium and magnesium phosphates, and bicarbonates of the
alkalies and calcium. Potassium sulphocyanide occurs in this saliva.
The Sublingual Saliva. The secretion of this saliva is also influenced
by the cerebral and the sympathetic nervous system. The chorda-saliva,
which is secreted only to a small extent, contains numerous salivary
corpuscles, but is otherwise transparent and very ropy. Its reaction
is alkaline, and it contains, according to Heidenhain,3
27.5 p. m. solids
(in dogs).
The sublingual secretion in man is clear, mucilaginous, more alka-
line than the submaxillary saliva, and contains mucin, diastatic enzyme,
and potassium sulphocyanide.
Buccal mucus can be obtained pure, from animals only, by the method
suggested by Bidder and Schmidt, which consists in tying the exit to
all the large salivary glands and cutting off their secretion from the mouth.
The quantity of liquid secreted under these circumstances (in dogs) was
so very small that the investigators named were able to collect only 2
grams of buccal mucus in the course of one hour. It is a thick, ropy,
sticky liquid containing mucin; it is rich in form-elements, above all
in flat epithelium cells, mucous cells, and salivary corpuscles. The
quantity of solids in the buccal mucus of the dog is, according to
Bidder and Schmidt,4
9.98 p. m.
Parotid Saliva. The secretion of this saliva is also partly dependent
on the cerebral nervous system (n. glossopharyngeus) and partly on the
sympathetic. The secretion may be excited by emotions and by irri-
1
Pfluger’s Arch., 1.
2
See Maly’s "Chemie der Verdauungssafte und der Verdauung," in Hermann’s
Handb., 5, part II, 18. This article contains also the pertinent literature.
3
Studien. d. physiol. Instituts zu Breslau, Heft 4.
* Die Verdauungssafte und der Stoffwechsel (Mitau and Leipzig, 1852), p. 5.
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