288 M. Wurzer on a Urinary CaUidus from a Hog. 



blueish tinge. Tlie ammonia, supersaturated by some drops 

 of nitric acid and mixed witli hydrocyanate of potash, gave a 

 peach-bloom precipitate, which indicated that the blue colour 

 which it had acquired was owing to a little copper. 



The oxide of iron separated by ammonia was calcined with 

 wax to produce the reduction of it, and in this state it was 

 entirely attracted by the magnet: it weighed 10 centigrammes. 



Thus it cannot be doubted but that this was iron in a state 

 of perfect purity. 



From this assay it results that the grains, considered as an 

 alloy of iridium and of osmium, are formed, in 20 parts, of the 

 substances hereafter designated. 



Portion insoluble in aqua-regia, five parts ; alloy of iridimn 

 and osmium, with traces of titanium and of chrome. 



Portion soluble in acjua-regia, fifteen parts ; of which ten are 

 iron, four platina, half a centigramme of copper, and some 

 traces of iridium. 



The small quantity of the ore raised by the magnet, and 

 which forms the tenth part, is composed of iron, of some atoms 

 of platina, and of the alloy of iridium and of osmium. 



The gray-coloured grains include more than a half of iron, 

 a little platina, and some of the alloy of iridium and osmium. 



As to the white grains, they appear to be almost entirely 

 formed of the alloy of iridium and osmium, although they also 

 contain a litUe platina and iron. 



XLVII. Analysis of an Urinary Calculus from a Hog. By 

 M. Wurzer, of Marburg*. 



THIS concx-etion had been cut in July 1S24-, at Fulda, from 

 the urethra of an emasculated pig under a twelvemonth 

 old. It had the size and shape of a small bird's egg. It 

 weighed 91 grains (new med. weight). Its specific gravity at 

 the temperature of 53° F. was r964. It was covered by a thin 

 lio-ht-ffrav crust, and when broken presented a radiated and 

 concentric crystallization. 



1. A fragment heated before the blowpipe soon became 

 brown, then black, and at last white again. During the pro- 

 cess the ammonia, being extricated, became distinctly per- 

 ceptible. 



2. 100 parts of this substance, heated on a water bath 

 until all the water had been expelled, lost 43*573. 



3. The pulverized stone boiled with distilled water, the 

 li(juid poured off, filtered and evaporated, gave a residuum 



• From Schweigger's Journal, Dand xiii. p. 300. 



of 



