URIC ACID. 217 



granules, which, as has been already stated, when seen under the 

 microscope, appear as dark globules, studded with a few acicular 

 crystals. It scarcely ever occurs except in urine which, by long 

 exposure to the air, has undergone the alkaline fermentation. Even 

 in the alkaline urine of patients with paralysis of the bladder 

 dependent on spinal disease, it is very rarely that I have found 

 these clusters of urate of ammonia. In the alkaline urine that is 

 sometimes passed in other conditions of the system, it is never 

 found. 



Uric acid, like urea, also exists in the blood; it has been found 

 there in healthy as well as in diseased states, and especially after 

 extirpation of the kidneys by Strahl and Lieberkiihn,* as well as 

 recently by Garrod,f who observes that in arthritis (but not in 

 acute articular rheumatism,) it is invariably, and in Brighfs dis- 

 ease it is very often, increased in the blood. 



My own observations for the most part confirm those of Garrod. 

 I first happened to convince myself of the presence of uric acid in 

 the blood of carnivora in examining the blood of a very large mas- 

 tiff who died in consequence of an artificial gastric fistula which I 

 had established. The serum was freed from its albumen by boiling 

 and with the aid of acetic acid ; the strongly evaporated filtered 

 fluid was extracted with alcohol in order that urea might be sought 

 for ; the residue, insoluble in alcohol, exhibited, under the micro- 

 scope, most unquestionable crystals of uric acid ; my attention 

 being thus drawn to the subject, I examined the blood of two 

 other dogs by the same mode of analysis, and convinced myself of 

 the presence of uric acid, not only by the microscope, but also by 

 the murexide test. Garrod asserts that he has often found uric 

 acid in the blood of healthy men, while Strahl and Lieberkiihn 

 failed equally in detecting it in the blood of men and of birds ; once 

 only they found uric acid in the blood of a dog; they recognised 

 it however with great distinctness, and on many occasions, in the 

 blood of frogs, dogs, and cats, after the extirpation of the kidneys. 

 Garrod found 0-005-J, 0'004-J, and, m one case, even 0'0175 of 

 uric acid in the serum of the blood of gouty patients. In acute 

 articular rheumatism he could only discover traces of uric acid in 

 the blood ; in Bright's disease the uric acid of the blood occurred 

 in very variable quantities ; (from 100 parts of serum he obtained 

 the following quantities, 0'0037, 0'0055, 0-0012, and 0*002? parts.) 

 In Germany we have few opportunities of repeating Garrod's 



* Harnsaure im Blut, u. s. w. Berlin. 1848. 

 t Medico-Chir. Trans. Vol. 31, pp. 8?-92. 



