66 PHELOSOPHY OF ZOOLOGY. 
gradually subsides, and it may then be collected on the 
filter and washed. In this state it is white, and would 
seem to contain phosphate of lime mixed with it. The 
mucus is quite insoluble in water *; it becomes transpa- 
rent and horny in the acetic, sulphuric and muriatic acids, 
but does not dissolve in them, and the alkalies separate 
nothing from them. The mucus, therefore, contains no 
earthy phosphate, though its appearance would lead to 
suspect this earthy salt. It dissolves in caustic alkali, and 
is again separated from it by the acids. A small propor- 
tion escapes the action of the alkali, but yields to muriatic 
acid, and is not separable from this acid, by an excess of 
alkali. The mucus of the saliva is very easily incinera- 
ted; and though no phosphate ‘of lime is detected m it 
by the acids in its natural state, a considerable portion of 
phosphate appears in the ash after combustion.” 
The mucus of the nose presents the following properties : 
‘* Immersed in water, it imbibes so much moisture as to 
become transparent, excepting a few particles that remain 
opaque ; it may then be separated by the filter from the rest 
of the water, and may be further dried on blotting paper, 
ull it has again lost nearly the whole of the moisture it had 
imbibed. Mucus thus dried will again absorb water when 
immersed in it, and resume its transparency ; ‘and this alter- 
nate wetting and drying may be repeated an indefinite 
number of times, but it thus gradually becomes yellowish 
and more resembling pus. Five parts of recent mucus 
absorbed by .95 parts of water, produce a glairy mass’ 
which will not pour from a vessel. When mucus is boiled 
with water, it does not become horny, nor does it coagu- 
late ; the violent motion of ebullition rends it in pieces, but 

* This was considered by Dr Bostock as albumen, and his mucus ap- 
pears to be the Peculiar Matter of the saliva of Berzexius. 
