SUBLINGUAL SALIVA. 343 
measurements gave for the submaxillary saliva 0*004 per cent., for 
the parotid 0-03 per cent., of this substance, reckoned as potassium 
sulphocyanate. It contains ptyalin, as shown by its powerful diastatic 
action on starch. 
The submaxillary saliva in the dog contains much more mucin than in 
man, and is in consequence much more viscid. It is alkaline in reaction, 100 
grms. requiring for neutralisation 0*135 to 0*144 grins, of sulphuric acid, 
reckoned as S0 3 . On standing in contact with air, calcium carbonate is 
thrown down as a flocculent precipitate, which was previously held in solution 
by the dissolved carbon-dioxide as bicarbonate. The same result is brought 
about more rapidly by heating. It contains, at most, only traces of proteid 
or of sulphocyanate. Its specific gravity is l - 0026 to 1*004. 
The quantitative composition of the saliva obtained on stimulation of 
the submaxillary gland varies according to the nerve stimulated. The 
saliva obtained on stimulation of the sympathetic (sympathetic saliva) 
is scanty in quantity, and contains much mucin, which gives it a viscid 
consistency. Chorda saliva, on the other hand, is plentiful in quantity, 
contains less mucin, and is hence a thin watery fluid. The chorda saliva 
has a specific gravity of 1*0049 to 1*0056, and contains 1*2 to 1*4 per 
cent, of total solids ; sympathetic saliva has a specific gravity of 1*0075 
to 1*018, and contains 1*6 to 2*8 per cent, of total solids. 1 
Parotid saliva. --Human parotid saliva may be obtained by intro- 
ducing a fine cannula into Stenson's duct. 2 
It is a thin, mobile fluid, usually clear, sometimes somewhat turbid, 
and contains no formed element save epithelial cells. It is alkaline in 
reaction, but the first few drops secreted may be neutral or acid, 
especially in a state of hunger ; in all cases the alkalinity is less than 
that of submaxillary saliva. 3 Its specific gravity seems to be very 
variable (Mitscherlich, 1*006 to 1*008; Oehl, 1-010 to 1*012 with scanty 
secretion, 1*0035 to 1-0039 with plentiful secretion; Hoppe-Seyler, 
1-0061 to 1-0088); the amount of total solids lies between 5 and 16 
parts per thousand. It contains traces of proteids, but is free from 
mucin : it also contains ptyalin and sulphocyanate. 
The parotid saliva of some animals, such as the dog and horse, is very 
rich in calcium bicarbonate, and often deposits crystals of calcium 
carbonate on standing. 4 Stimulation of Jacobson's nerve in the dog 
produces a flow of saliva from the parotid, poor in organic constituents. 
If, before this is done, the cervical sympathetic be stimulated, which 
alone produces no effect, on now stimulating the nerve of Jacobson 
a flow of saliva is obtained which is much richer in organic con- 
stituents. 5 
Sublingual saliva.- Oehl attempted to obtain human sublingual 
saliva by a similar method to that described in the case of the other two 
glands ; he was only able to obtain a very small quantity, insufficient for 
1 Eckhard, Beitr. z. Anat. u. Physiol. (Eckhard), Giessen, 1860, Bd. ii. For further 
details regarding the influence of nerves on the composition of saliva, see article on 
'' Mechanism of Salivary Secretion." 
2 Eckhard, he. cit. ; Oehl, Jahresb. ii. d. Fortschr. d. ges. Med., Erlangen, 1865, Bd. i. 
S. 120. See also Brunton in Sanderson's "Handbook of the Physiol. Laboratory," p. 467. 
3 See Astaschewsky, Jahresb. il. d, Fortschr. d. Thier-Chem., Wiesbaden, 1878, Bd. viii. 
S. 234 ; Fubini, ibid., S. 235. 
4 Lehmann, "Physiol. Chem.," Bd. ii. S. 13. 
5 Heidenhain, Arch. f. d. ges. Physiol., Bonn, 1878, Bd. xvii. S. 28 ; also in Hermann's 
"Handbucb," Bd. v. (1), S. 55. 
