

Mr. Cock on Artificial XJranite. 387 



which may easily he oxalate of ammonia, effected perhaps somewhat 

 after the following fashion : — 



Uric acid C 5 H 2 N 2 3 1 C 2 eq. oxal. acid C 4 6 



4 eq. water H 4 4 > = < 2 . . ammonia H 6 N 2 



1 eq. oxyg. from air O J Ll .. carb.acidC 2 



C s H 6 N s 8 C 5 H 6 N 2 8 



This view, it must be remembered, is merely hypothetical, yet is 

 borne out by the facts. 



The only case in which oxalic acid is known to arise from uric 

 acid, is in the artificial formation of allantoin discovered by Liebig, 

 and in which uric acid, water and peroxide of lead being boiled 

 together, give rise to oxalate of the protoxide of lead, allantoin and 

 urea ; it is in short an oxidizing action, so far resembling the one 

 imagined, but more complex. 



Uric acid (doubled) C 10 H 4 N 4 6 ] f Allantoin. . . . C 4 H 3 N 2 3 



3 eq. water H g 3 > = I Urea C 2 H 4 N 2 2 



2. . ox. fromperox. 2 J (^2 eq. oxal. acid C 4 6 



C 10 H 7 N 4 O n C 10 H 7 N 4 O u 



It is very unlikely that this peculiar mode of decomposition 

 should occur under the circumstances in which the guano is pro- 

 duced ; urea certainly would not resist destruction a week, and no 

 doubt the allantoin would share the same fate. 



It was thought worth while nevertheless to examine one of the 

 specimens (No. 1) carefully for these two bodies, a portion of the 

 substance being acted upon by hot water, and the filtered solution 

 cautiously evaporated to a small bulk, whereupon crystals were 

 abundantly formed on cooling. These being dissolved in hot water, 

 decolorized with animal charcoal, and the solution once more con- 

 centrated, a second crop was got, but slightly coloured. These 

 however turned out on examination to be nothing but oxalate of 

 ammonia. The search for urea was equally unsuccessful. 



There is a curious relationship between the three bodies, oxalate 

 of ammonia, oxamide and allantoin, the only difference in compo- 

 sition being the diminishing proportion of the elements of water. 

 Anhydrous oxalate of ammonia (doubled) . . C 4 H 6 N 2 6 



Oxamide (doubled) C 4 H 4 N 2 4 



Allantoin C 4 H 3 N 2 3 



" On the production of Artificial Uranite," by W. J. Cock, Esq. 



The subject of the present communication was observed during the 

 preparation of the oxide of uranium from its mineral, Pitchblende ; 

 it was obtained as follows : — 



The mineral was pulverized and well calcined ; it was then di- 

 gested with diluted nitric acid, which dissolved the greater part of 

 the soluble contents. (From this solution none of the precipitate 

 was obtained.) 



The undissolved residuum was washed and dried, and again cal- 

 cined. It was digested in nitric acid rather stronger than before, 



