S°5 
and Experiments on Pits . 
saturation with the fixed alkalies, but a trifling sediment 
appeared, which re-dissolved on the addition of the above 
acids. 
2. The mineral acids diluted, or added in small proportion, 
and the vegetable acids, coagulate variously pus and mucous 
fluids. Some become merely milky fluids, others curdy fluids, 
others afford fibrous and leafy masses in a transparent liquor, 
and others give an uniform thick mass of curd. On standing 
the deposits are accordingly of various forms, and the liquors 
above of various appearances, but I could discover no constant 
characteristic property of the substances by these experiments, 
as some writers have asserted. 
3. The solid fixed alkalies, or lime, mixed with expectorated 
mucus, occasion a stronger smell of ammonia than with pus ; 
or than with muco-purulent sputum. Some use may be per- 
haps made of this easy experiment to judge of the nature of 
varieties of the fluids in question, particularly as far as depends 
on the proportion of ammonia : for sometimes it cannot be 
perceived by the smell on mixing alkalies, but can by muriatic 
acid giving white vapours. Concentrated liquid alkalies, added 
to both pus and mucus, dissolve them to produce clear liquids, 
except small curdy parts and motes. These curdy parts and 
motes resist dissolution also for some time even in nitric acid, 
and seem to be self-coagulated lymph. They are in much 
greater proportion in pus than mucus. The addition of acids to 
these alkaline dissolutions, occasions precipitations, but no diffe- 
rences, cr not with sufficient uniformity to afford criteria, were 
observed according to the observations of other Experimenters. 
4. Concentrated aqueous solutions of various neutral salts, 
viz . muriate of ammonia; nitrate of potash; muriate of soda; 
