6 
PROCEEDINGS OF THE ACADEMY OP 
[Biolog. 
bronchitis, typhns fever, spermatorrhoea, and dyspepsia. In these diseases, 
we have either a disturbed respiration or an excessive retrograde tissue- 
metamorphosis ; and to these we must look to discover the cause of the ap- 
pearance of oxalate of lime in the urine. The changes which the substances 
introduced into the animal system undergo, are those of progressive oxida- 
tion ; hence it is easily seen that a diminished supply of oxygen, or an increased 
waste of tissue, would be accompanied by an imperfect oxidation. 
But from being regarded as a pathological constituent of high importance, 
oxalate of lime has now come to be considered an almost normal substance in 
the urine. It may be found in almost any specimen of urine which has been 
allowed to stand until the acid fermentation has occurred. Dr. Grolding Bird 
believes the cause of this to be its deposition from a sort of solution in the 
urine, an opinion in which I cannot concur, as proof is wanting that it is solu- 
ble in any urine. It is well known that urine undergoes an acid fermentation, 
commencing soon after its expulsion from the bladder, and continuing for some 
days, during which uric and oxalic acids are formed ; after a time, however, a 
second fermentation occurs, in which the urea is converted into carbonate of 
ammonia. ' What explanation can we give of the occurrence of these apparent- 
ly opposite phenomena in the same liqjiid under the same circumstances ? The 
ferment which acts in both cases is probably the vesical mucus ; and the sub- 
stance changed must be either this mucus, the coloring matter, or the creatin 
and creatinin, as these are the only other nitrogenized substances present. 
That it cannot be the mucus is proved by filtering the urine, after which it still 
ferments, though more slowly. That it is connected with the presence of 
rreatin may be inferred from the fact that Dr. Miltenberger and I (Med. Ex- 
aminer, 1854) have found crystals of creatin formed by spontaneous evapora- 
tion in microscopic specimens of urine containing oxalate of lime. If we take 
Hg N3 O4 as the composition of creatin, two equivalents of the latter, with 
14 of the oxgen would yield 1 equiv. of uric acid, 1 of urea, 2 of oxalic acid, 
and 8 of water, thus : 
2 ( Cs H. N3 O4 ) 4- 14 0 = Co H4 N4 Og + C2 H4 N2 O2 -f 2C2 O3 8H0. 
I suppose some such reaction as this to take place as long as any creatin re- 
mains in the urine, thus explaining the acid fermentation ; when this has 
(..•eased to occur, the urea decomposes into carbonate of ammonia. This will 
also explain the crystallization of the oxalate ; for, as this is a slow process, 
the oxalic acid is very slowly presented to the lime-salts of the urine, thus 
falfiUing the condition given by Lehmann as necessary for the formation of the 
crystals. Prof. Jones, of Georgia, succeeded in obtaining them by endosmose, 
to which he attributes this formation; but this is obviously only another 
method of very gradually presenting the oxalic acid to the lime, the main con- 
dition requisite for their formation. 
Dr. Hammond observed, that he had frequently found oxalate of lime in the 
urine, in his own person and that of others, during health ; large crystals, both 
of the dumb-bell and octohedral forms being presented. Dr. Hammond does 
not credit the existence of an "oxalate of lime disease," nor of a diathesis, 
such as is described by some English pathologists, characterized by excess of 
urea. 
Feb. 15th. Dr. T. G. Richardson read an elaborate paper by Dr. George 
Paton, of Gait, Canada West, upon the Functions of the Spinal Cord, as illus- 
trated by experiments on cold-blooded animals ;* endeavoring to show occasion for 
some modification of the theory of reflex action of Marshall Hall, and for the 
opinion that perception is one of the attributes of the spinal cord, and especially 
of the medulla oblongata. 
Dr. Leidy remarked that the experiments narrated in the paper did not ap- 
pear to him entirely conclusive, as the movements described might be auto- 
* See N. Amer. Medico-Chiurg. Review, May, 1858. 
[April, 
