Products of the Decomposition of Uric Acid. 189 



retaining probably its original form. Or they may have exa- 

 mined a mixture of the crystals of both, in which those of 

 dialuric acid happened to be the largest and best formed. 

 Such a mixture, if analysed, would of course yield results 

 closely approximating to those derived from alloxantine, as 

 the latter body consists of the same elements as dialuric acid 

 + 1 at. of hydrogen and 2 at. of oxygen only. Liebig and 

 Wohler have already observed, and my experiments confirm 

 the statement, that the liquid obtained by boiling dialurate of 

 ammonia with an acid, deposits, when allowed to stand for 

 some time after cooling, crystals of alloxantine, which will of 

 course be found mixed with the dialuric acid deposited during 

 refrigeration, unless the latter be first separated. 



The salts of dialuric acid in the dry state are quite perma- 

 nent. I am still occupied with the study of this remarkable 

 acid and its salts. 



4. Acid Thionurate of Ammonia. 



This salt, from which, according to Liebig and Wohler, 

 the uramilic acid is best obtained, may be prepared in any 

 quantity by dissolving the neutral thionurate of ammonia in 

 hot water, and adding exactly as much hydrochloric acid, 

 calculated from the specific gravity by means of the published 

 tables of liquid hydrochloric acid, as corresponds to 1 eq. of 

 hydrochloric acid for 1 eq. of the salt, which contains 2 eq. of 

 ammonia. One of these is removed by the hydrochloric acid, 

 and when the liquid is gently evaporated to a small bulk it 

 deposits the acid (monobasic) thionurate of ammonia in soft 

 crusts, which frequently fall to the bottom, and are composed 

 of very minute prisms. I have not yet succeeded in obtaining 

 uramilic acid either from this salt or in any other way; and 

 Prof. Liebig informs me, that neither he nor Prof. Wohler 

 has been so fortunate as to succeed in procuring it again. It 

 can hardly be doubted, however, that with an easy and sure 

 method of preparing the acid thionurate, we shall soon ascer- 

 tain all the conditions essential to the formation of uramilic 

 acid. The acid thionurate itself, as well as all the compounds 

 now mentioned, I have prepared by ounces at a time without 

 once failing. 



5. Alloxano- sidphurous Acid. 



Liebig and Wohler mention that a solution of alloxan in 

 sulphurous acid, when slowly evaporated, deposited large ta- 

 bular acid crystals, which not only were not thionuric acid 

 (which requires the elements of ammonia besides those of al- 

 loxan and sulphurous acid), but, when mixed with ammonia, 

 did not produce the thionurate of that base but a totally dif- 



