indurated albumen. 
624 
for this reason, is technically known as the mul- 
berry calculus; and it is very hard, compact, 
_ dark-coloured, and tuberculated. A rare kind of 
calculus was called by Dr. Wollaston cystic oxide, 
on account of its behaving like an oxide and seem- 
ing to be peculiar to the bladder; but it differs 
in constitution from the ammoniaco-magnesian 
phosphate principally in being more compact, 
and has been found in the kidney; and it does 
not possess concentric layers, but appears a con- 
| fusedly crystallized and somewhat uniform mass. 
A compound urinary calculus consists of an in- 
timate mixture of the ingredients of different 
kinds of calculi; and an alternating calculus con- 
sists of alternate layers of the ingredients of two 
or more kinds; but neither of these has ever been 
known to comprise any cystic oxide. A calculus 
| of a yellow or reddish-yellow colour has been 
called xanthic oxide on account of its yellowness 
| and its oxidal behaviour; another possesses pro- 
| perties closely similar to fibrin, and has been 
called the fibrinous calculus; and another con- 
sists principally of carbonate of lime; but all these 
three are of exceedingly rare occurrence. Silice- 
ous matter appears occasionally to be found in 
| some urinary calculi, but seldom or never in such 
| quantity or with such effect as to produce any 
| characteristic property or appearance. 
The urinary calculi of the lower animals, though 
quite similar to those of man in their nosological 
connexions, considerably differ in their chemi- 
cal composition. Uric acid, in an uncombined 
state, does not seem to occur in any; and, even 
in a combined state, occurs in very few. The 
ammoniaco-magnesian phosphate occurs prin- 
cipally in the hog, and, with the addition of 
| animal gluten, constitutes nearly all the urinary 
calculi of that animal. Carbonate of lime con- 
stitutes about 91 per cent. of the urinary calculi 
of the ass, 87 per cent. of those of the ox, and 83 
per cent. of those of the horse; and the other in- 
gredients are principally phosphate of lime and 
animal gluten. A calculus which was extracted, 
a few years ago, from the bladder of a mare in 
Aberdeenshire was found to be eight ounces in 
weight, and to consist of about 40 per cent. of 
| carbonate of lime, and about 60 per cent. of ani- 
mal matter, apparently mucus of the bladder and 
A calculus taken, not long 
ago, from the urethra of a pig at Boonjedward in 
Roxburghshire, exhibited considerable resem- 
_ blance to many of the calculi which are extracted 
from man. “The external surface, presenting a 
beautiful, white, crystallized appearance, was com- 
posed of a triple salt,—the phosphate of magnesia 
and lime; the interior, a dark brown portion, 
| also in a crystallized state, was composed of uric 
acid in combination with these phosphates.” Sili- 
ceous sandy particles occasionally lodge and even 
accumulate in the bottom of the bladder of every 
kind of domestic animal. Numerous small calculi 
frequently occur in many of them, and occasion 
| retention of urine and apparently severe pain. 
CALCULUS. 
Calculi of comparatively great size and weight, 
exciting disease and even inducing death, some- 
times occur in various domestic animals, parti- 
cularly in the dog, the ox, and the horse. 
Minute calculi sometimes pass spontaneously 
away with the urine, or, if reluctant to pass with 
it, may be incited forward by the force of diuretic 
medicines. But calculi which are not quite 
minute, and especially calculi of any consider- 
able size, can be prevented from accumulating 
till they prove fatal, only by being extracted en- 
tire, or by being so broken and triturated that 
they can pass with the urine, The surgical opera- 
tions for effecting their extraction or reduction 
are, in most instances, performed very success- 
fully on man, and have often, especially of late 
years, been performed successfully on domestic 
animals ; and they will be described in our articles 
Litrnoromy and Lirnorriry. 
Speculations many and sanguine have been en- 
tertained as to the possibility of dissolving cal- 
culi, so as to dispense with lithotomy or litho- 
trity, and to make the materials of the calculi 
pass off with the urine. “ From the solubility of 
urinary concretions in chemical menstrua,” says 
Dr. Turner, “hopes were once entertained that | 
reagents might be introduced into the urine 
through the medium of the blood, or be at once 
injected into the bladder, so as to dissolve uri- 
nary calculi, and thus supersede the necessity of 
a painful and dangerous operation. It has been 
found, however, that, for this purpose, it would 
be necessary to employ acid or alkaline solutions | 
of greater strength than may safely be introduced 
into the bladder; and consequently all attempts | 
of the kind have been abandoned. The last sug- | 
gestion of this nature was made by Messrs. Pre- 
vost and Dumas, who proposed to disunite the | 
elements of calculi by means of galvanism. This 
agent, however, though it may produce this effect | 
out of the body, will scarcely, I conceive, be found 
admissible in practice.” Yet though the idea of 
dissolving the strongly indurated and densely 
crystalline calculi of man may be somewhat vi- 
sionary, the proposal for dissolving or disinte- 
grating the calcareous matters which form the 
chief bulk of most of the calculi of herbivorous 
animals, may be perfectly feasible, and of consid- 
erable practical value. “From the composition 
of the calculi in these animals,” says Professor 
Dick, “ they may be dissolved in the bladder, and 
discharged in a fluid state. This may be done 
by employing muriatic acid, which, having a 
strong affinity for lime, will, by the administra- 
tion of a sufficient proportion of it, dissolve the 
calculi, and discharge them with the fluid. And 
this would, in some cases, be the more readily 
effected, as it sometimes happens that the cal- 
cular deposit remains in a semifluid state for a 
considerable time in the bladder, of which I once 
met with a remarkable instance. 
sent to me, for examination, from Fife, which, 
with its appendages, contained the enormous 
A bladder was | 
