1 86 Miscellanies. 



began to boil at 28° cent, and continued at that point till it was all 

 evaporated. Its specific gravity was 1.455. It is decomposed in con- 

 tact with water, into nitric acid, and oxide of azote ; in a word, 

 it presents all the properties of the compound of nitrous acid with ni- 

 tric acid discovered by Dulong. On the contrary, the heavy fluid be- 

 ing heated, its boiling point rose continually from 28° to more than 

 126° progressively as the distillation was continued. 



This liquid is of an intense red color like common fuming nitric 

 acid. It becomes colorless when about one half is distilled off. The 

 product is about one half of the light and one half of the heavy liquid. 

 The specific gravity of the latter is 1.539. Common fuming nitric 

 acid acts in the same manner. 



It results from these experiments that fuming nitric acid is a solu- 

 tion of hypo-nitric acid in nitric acid, which however can dissolve 

 only a certain quantity, about half of its weight, so that in distilling 

 common fuming nitric acid, we obtain a heavy liquid, (viz. a saturated 

 solution of nitrous acid in nitric acid,) and a lighter fluid, viz. hypo- 

 nitric acid. — Idem. 



5. On the decomposition of Water, by C. Despretz. — It has been 

 long known that red hot iron decomposes water and disengases hy- 

 drogen gas, and that a current of this gas, removes entirely the oxy- 

 gen from the oxide formed. Gay-Lussac has shewn that the decom- 

 position and recomposition of water takes place at the same tempera- 

 ture. I find that zinc, nickel, cobalt and tin act like iron. The ox- 

 ide of manganese is not completely reduced by hydrogen. Some 

 pure peroxide of that metal, exposed to a current of the dry gas, in 

 the highest heat of a good forge, left a portion of melted protoxide, 

 of a very fine green color. — Idem. 



6. Decomposition of Carbonic Acid, by C. Despretz. — Carbonic 

 acid presents the same phenomena as water ; it is brought to the con- 

 dition of oxide of carbon by iron, zinc, and tin, and the oxides of 

 these metals are reduced by the second gas. 



The oxide of carbon was prepared by a mixture of oxalate of pot- 

 ash and sulphuric acid, and deprived of any acid which it might en- 

 tangle by an alkaline solution. — Idem. 



7. On crystallizable Acetic Acid, by C. Despretz. — The process by 

 which crystallized acetic acid is prepared, is kept a secret. After 

 many trials I succeeded in obtaining very fine specimens by heating 

 a mixture in atomic proportions of melted and dried acetate of lead 

 'and boiled sulphuric acid, (203.4 parts of the former, and 61.4 of the 



