ITS ABNORMAL CONSTITUENTS. 425 



to detect true casein in urine ; but in all the analyses of chylous 

 urine, instituted by Chevallier,* Blondeau,t Rayer,J Bouchardat, 

 Golding Bird, || and others, the evidence of the presence of casein is 

 by no means established with scientific accuracy ; for if it were, we 

 must believe in a perfect metastasis of milk to the kidneys. It is, 

 however, an unquestionable fact, that there do sometimes occur in 

 the urine certain protein-bodies whose properties do not coincide 

 with those of any known protein-compound, and whose modifica- 

 tions cannot be solely dependent on their admixture with the 

 urinary secretion. Thus, for instance, Bence Jones^f found a peculiar 

 albuminous substance, together with the well-known tubular casts, 

 in the urine of a man suffering from osteomalacia and from a renal 

 disease; this substance was characterised by its solubility in 

 boiling water ; when precipitated by nitric acid it redissolved on 

 the application of heat, but again separated on cooling ; with acetic 

 acid and ferrocyanide of potassium it behaved precisely as a 

 protein-body, as also with concentrated hydrochloric acid, forming 

 with it a brilliant purple solution ; moreover, its elementary 

 analysis showed that its composition was altogether analogous to 

 that" of the protein-bodies; it contained 1'1-g- of sulphur, which 

 could be very easily recognised on treating it with potash, &c. 

 The urine contained 6'7{f of this substance, which cannot possibly 

 be regarded as either albumen or casein, at all events until we 

 are able by the addition of certain substances either to convert 

 albumen or casein into this substance, or it into them ; it presents 

 too many points of difference to allow of our regarding it as a 

 modification of any of the known protein-compounds. 



Fat is comparatively rarely found in the urine, if we exclude 

 the admixture of fatty matter that often arises from the external 

 generative organs of women. In the older medical literature we 

 often read of fatty urine, in which the fat collected as an iridescent 

 film upon the surface ; but in the great majority of cases these 

 membranes must have consisted of the crusts of earthy phosphates 

 and confervoid filaments, which have been already described, and 

 not of fat: for these crusts are often singularly like a coating of 



* Journ. de Chim. meU T. 4, p. 179. 



f Ibid. Vol. 4, p. 41. 



$ L'Expe'rience. 1838. No. 12. 



Joiirn. de Connaiss. med. Aout, 1843. 



II Loud. Med Gaz. Oct. 1843. 



T[ Ann. d. Ch. u. Pliarin. Bd. 07, S. 97-105 [and Philosophical Transact 



for 1843, p. 55]. 



