806 
crimson liquid is obtained, with nitric a yellow 
solution attended with effervescence during the 
action, and with hydrochloric acid a character- 
istic violet-coloured liquid is procured. 
e. The gelatinous tissues may be shewn to be 
such by continued boiling in water for twenty- 
four or forty-eight hours; the liquid, if not too 
dilute, has then the property of gelatinizing on 
cooling; with infusion of galls it should pro- 
duce an abundant flocculent buff-coloured pre- 
cipitate. 
J. Sometimes we meet with concretions formed 
principally of Aairs; their texture and appear- 
ance generally betray their composition. Be- 
fore the blowpipe they are dissipated with the 
well-known smell of burnt feathers. Solution 
of potash dissolves them slowly, and the liquid 
then gives the reactions furnished by alkaline 
solutions of albumen. 
g. Earthy phosphates—Phosphate of lime 
rarely occurs alone, either as a sediment or cal- 
culus; though in combination with others it is 
one of the most usual constituents of morbid 
concretions. Before the blowpipe, unless mixed 
with animal matters, it undergoes little change ; 
usually a transient blackening appears from the 
charring of a little organic matter always pre- 
sent; by continuing the heat it becomes white. 
Nitric acid dissolves it readily, and phosphoric 
acid may be shewn by adding acetate of lead 
as directed when speaking of the detection of 
phosphoric acid. Ammonia in excess added 
to the acid solution causes a bulky gelatinous 
precipitate of bone earth; on redissolving in 
acetic acid, and adding oxalate of ammonia, 
we obtain abundance of oxalate of lime. 
Phosphate of ammonia and magnesia, or, as 
it is frequently termed, triple phosphate, is a 
common constituent of calculi and of white 
sand; when in the form of a sediment it ge- 
nerally occurs in hemihedral six-sided prisms ; 
heated before the blowpipe it emits ammonia, 
agglutinates, but is almost infusible; the addi- 
tion of a fourth or a sixth of its bulk of phos- 
phate of lime, as a shaving of bone or ivory, 
causes its immediate fusion to a white enamel- 
like bead. It is soluble in acids, and ammo- 
nia causes a crystalline precipitate of unchanged 
phosphate ; a horic acid may be discovered 
by acetate of lead as before; oxalate of ammo- 
nia causes no precipitate in the acetic solution 
unless lime be present. 
Not unfrequently these two kinds are mixed, 
constituting what has been termed the fusible 
calculus, from its property of forming the ena- 
mel-like bead before the blowpipe just men- 
tioned. Heated with potash it evolves ammo- 
nia. Phosphoric acid and lime may be shown 
as before. After the separation of lime b 
oxalate of ammonia, supersaturation wit! 
ammonia throws down the crystalline phos- 
hate of ammonia and magnesia. 
h. Carbonate of lime.—These calculi be- 
fore the blowpipe are converted into caustic 
lime, and then give a brown stain to turmeric 
paper. In dilute nitric or hydrochloric acid 
they dissolve with effervescence. Lime may 
be shown in the solution by appropriate tests. 
ORGANIC ANALYSIS. 
i. Oxalate of lime is now and then met 
with, forming a gravel crystallized in pale 
amber-coloured prisms, but usually in the — 
form of larger concretions, from their tuber- 
culated exterior termed mulberry calculi; for 
the most they have a dark brown or ma- 
hogany colour. Heated moderately before the 
blowpipe they yield a white ash, ing 
principally of carbonate of lime, and dissolving 
with effervescence in acids. If the heat be 
greater, quicklime alone remains. It stain: 
turmeric paper brown when moistened. Lim 
may be detected in the ash by the usual 
agents. Oxalate of lime, when powdered, di 
solves in nitric acid readily, more sparing 
hydrochloric acid. Ammonia throws it doy 
unchanged from these solutions, and the pre: 
pitate is insoluble in acetic acid. 
The whole of the preceding experiments ma 
be made upon portions of matter not exceedin 
two grains, and most upon a quantity mue 
smaller, especially if our examinations 
aided by the microscope. Examinations | 
these matters are rarely quantitative; the sm 
quantity of material procurable, and an unw 
ingness to sacrifice morbid products of t 
description for the purposes of analysis, prev 
us from possessing information so full a 
detailed upon the constituents of concretit 
in general as the numerous collections in e 
tence would have led us to expect. 
Calculi, especially urinary calculi, ar 
from presenting a uniform and homoger 
structure throughout, being in many if n 
most cases composed of lamine differing m 
rially in composition. It would be of I 
value to the pathologist to know the cor 
nents of all the different layers mingled 
criminately ; the information he would deri 
to the process by which the stone was for 
and of the means by which tendencies to. 
formations might be counteracted, would | 
the most confused and indefinite deseri 
tending rather to mislead than to aid h 
forming correct conclusions. Just so it i 
chemical analysis is applied to organize 
tures in general without due regard to the 
ture and disposition of the proximate 
within them; and hence the confused n 
of substances obtained by subjecting the 
whole to the action of chemical agents. 
texture, however, once known, and the 
of our reagents upon it being watched 
the field of the microscope, we can at pl 
separate the different ingredients, and 
with comparatively little difficulty, ~ 
which are fixed and producible at will; 
which strictly belong to the domain of & 
to whose enlargement and successful cult 
they then really contribute. ‘s 
When soft tumours or malignant grov 
submitted to our examination, one portiol 
as usual be carefully desiccated, to di 
the proportion of moisture ; and anothe 
being shred finely, macerated for some 
with water at a temperature not exceedr 
F.; in this way the soluble albumen 
separated from the fibrous and other 
. 
ODSISLUD ‘ 
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