1820.] Dr Henry on Urinary Calculi. 115 



ing matter remains dissolved. It is probably derived originally 

 from effused blood, for the smooth vaiiety of calculus which con- 

 sists chiefly of oxalate of lime, is not distinguished by this dark 

 shade of colour. 



Ci/slic Oxide CakuJi. 



By means of Dr. Woliaston's clear description of this rare 

 Variety of calculus, I have recognised two specimens of it in my 

 own collection, but with the histories of both 1 am wholly unac- 

 quainted. They have obviously been extracted from the bladder; 

 the one, when entire, weighing 660 gr. and the other 334. la 

 each, the nucleus is the same substance as the rest of the con- 

 cretion ; and in a third specimen, also in my possession, a very 

 small spherule of cystic oxide forms the nucleus of a moderately 

 sized calculus, the rest of which consists of uric acid. This oxide 

 appears, therefore, as Dr. Marcet has properly remarked, to be ia 

 reality the production of the kidneys, and not, as its name would 

 import, to originate in the bladder. 



Calculi, the Ingredients ofivhick are disposed in alternate Layers, 

 Of these I have little more to observe than will be suggested 

 by inspecting the tirst table; viz. that calculi composed of layers 

 of uric acid and the earthy phosphates are, in the collection* 

 which I have exammed, the most frequent variety of the alter- 

 nating kind ; next follow those of oxalate of lime and the phos-. 

 phates ; then concretions of oxalate of lime alternating with uric 

 acid ; and lastly, those occur most seldom in which the three 

 substances just mentioned alternate together. I have not met 

 with an instance of a calculus containing four ingredients in 

 distinct layers ; and it appears, from the testimony of others^ 

 that such examples are extremely uncommon. 



Foreign Substances voided in the Urine. 



I have related, in a periodical medical journal,* the case of 

 an elderly gentleman, who discharged in his urine the larva> of 

 an insect, which, when first voided, were alive and vivacious, 

 and so far as could be made out by an eminent naturalist^ 

 belonged to some species of the coleopterous order. In this 

 case, though the patient would not consent to be sounded, there 

 was doubtless a stone in the bladder, and, as appeared to me, 

 extensive disease of the bladder itself and of the prostate gland; 

 but no examination I believe was made after his death, which 

 was occasioned suddenly by a lit of apoplexy. 



I have lately been made acquainted, by a gentleman of middle 

 ajje, with a singular discharge which he' frequently observes in 

 his urine, of a considerable number of short hairs. Besides that 

 he is above all suspicion of being deceived himself, or deceiving; 

 others, I have satisfied myself, by the most careful iavesligation^ 



* Edin. MeJ. Journ. vii. 14T. 



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