550 Dr. Gregory on the Preparation of Alloxan. 

 Measurements of Guanite, 



MonM'. 

 M on/ . 

 M'on/ . 

 M' on h . 

 /on h . , 

 M on e . 



57 0, 30 

 118°'30 

 118°'30 

 151°-00 



89°'30 

 142°- 10 



M 



f 



M 



M' on e 



li on c . 

 e on e 1 . 

 eonf . 

 e' on /' 

 e on c . 



142°- 10 

 133°-20 

 91 o, 50 

 112°-20 

 112°-20 

 142°-10 



LXXXV. Notes on the Preparation of Alloxan. 

 By William Gregory, M.D., F.R.S.E* 



TN an interesting and able paper on alloxan and its de- 

 ■*• rivatives, the first part of which appears in Liebig's An- 

 nalen for September 1845, Schlieper enters into minute details 

 concerningthe mostadvantageous method of preparing alloxan, 

 and after describing the results which he obtained on repeat- 

 ing the process given by me, proposes a new method of his 

 own, which he considers in every way preferable, as yielding, 

 with greater facility and certainty, a larger proportion of al- 

 loxan. Professor Liebig in his Lectures (Lancet 1845) also 

 recommends Schlieper's method as the best in every respect. 



I am still, notwithstanding, inclined to give a decided pre- 

 ference to my own process, when carefully performed, and 

 that on the grounds of its superior simplicity, facility and pro- 

 ductiveness. A brief comparison of the two methods, with 

 their results, will enable the reader to judge for himself. 



I must first of all, however, observe, that Schlieper, in re- 

 peating my process, has not obtained results so favourable as 

 I had formerly announced ; so that, in his hands, his own me- 

 thod has been the more productive. I formerly obtained from 

 100 parts of uric acid 90 of crystallized (hydraled) alloxan, 

 perfectly pure, not reckoning the portion of alloxan remain- 

 ing in the mother-liquids. Schlieper, on the other hand, from 

 15 ounces of uric acid, treated by my process, obtained, in- 

 cluding the contents of the mother-liquids, 8 ounces hyd rated 

 alloxan, If ounce alloxantine (= 2} ounces alloxan), and 

 f- ounce parabanic acid ; in all equivalent to about 11 £ ounces 

 of alloxan. This only amounts to 75 per cent. ; whereas I 

 obtained 90 per cent., exclusive of the mother-liquids, which 

 I find on an average to yield fully one-tenth more; in all, 

 therefore, at least 100 per cent. I may here state that I have 



* Communicated by the Chemical Society; having been read December 

 15, 1845. 



