as* Intelligence and Miscellaneous Articles. 



silver is characteristic ; it forms %vith them, after being neutralized 

 by ammonia, a j^ellow precipitate, which on being gently heated is 

 reduced to the metal with a rapid effervescence. The above-men- 

 tioned lead salt yields, on analysis, 80'4 per cent, of oxide of lead ; 

 it contains a slight admi.^cture of a substance containing nitrogen, 

 probably cyanatc or cyanurate of lead, from which it cannot be per- 

 fectly purified. The composition of the lead salt is very probably 

 expressed by the formula C,,04 -f 2PbO, in which case its formation 

 from alloxan and alloxanic acid admits of a ready explanation. From 

 1 eq. alloxan 1 eq. urea is separated, by which 2 eq. of anhydrous 

 mesoxalic acid is left. 



1 eq. alloxan =C8N2H40|o 



— 1 eq. urea =C3N3H^O ., 



= 2 eq. mesoxalic acid=Cg Og 



The above-mentioned mesoxalate of baryta contains 56 per cent. 



of baryta, from which its constitution is probably represented by the 



, „ ^ , /BaO. 

 formula V-/JU4 + < j^q 



MYKOMELINTC ACID. 



Discovered by Wohler and Liebig. Product of the decomposition 

 of alloxan by ammonia. It is prepared by heating to 212 a solution 

 of alloxan with an excess of ammonia, then neutralizmg with an 

 excess of dilute sulphuric acid and boiling for a few minutes. The 

 mykomelinic acid falls as a yellow gelatinous precipitate, which 

 dries to a yellow porous powder ; it is with difficulty dissolved by 

 cold, but more readily by hot water ; the solution has a distinctly 

 acid reaction ; it decomposes the carbonated alkalies and is easily 

 dissolved by the caustic alkalies, but on being boiled with them is 

 decomposed with the evolution of ammonia; it forms, with the oxide 

 of silver, a yellow compound, which is insoluble in water. It is 

 produced by the decomposition of 1 eq. alloxan and 2 eq. ammonia 

 into 1 eq. mykomelinic acid and 5 eq. water. 



Its formula is probably Ci,N4H305. 



PARABANIC ACID. 



Discovered by Wohler and Liebig. Product of the decomposi- 

 tion of uric acid and alloxan by nitric acid. Prepared by treating 

 1 part of uric acid, or 1 part of alloxan, in 8 parts of pretty strong 

 nitric acid, evaporating to the consistence of a syrup, and allowing 

 it to stand for some time, Avhen it yields colourless crystals which 

 may be purified by a second crystallization. 



Properties. — Colourless, transparent, thin, hexagonal prisms ; has 

 a strong acid taste, very similar to that of oxalic acid ; is very so- 

 luble in water, does not effloresce either in the air or in a warm 

 room; fuses if heated, when a portion sublimes unchanged, but an- 

 other part decomposes with the evolution of hydrocyanic acid. The 

 cold solution neutralized by ammonia produces a white precipitate 



