Intelligence and Miscellaneous Articles, 397 



tion, but by spontaneous evaporation acicular crystals are obtained. 

 Valerianate of barytes is an amorphous mass, unalterable in the air; 

 the valerianates of lime and magnesia crystallize in needles, which 

 are not deliquescent. Valerianate of lead deposits in laminar cry- 

 stals from a hot solution : by evaporating the liquor a thick syrupy 

 fluid is obtained. 



With the oxides of mercury valerianic acid forms two salts. The 

 protovalerianate is but little soluble ; a saturated boiling solution 

 deposits small needles on cooling. The pervalerianate of mercury is 

 much more soluble : if the solution is boiled with an excess of prot- 

 oxide, a bright yellow pulverulent subsalt is deposited on standing. — 

 Journal de Chimie Medicate, Sept. 1834, p. 473. 



HYDROCYANIC iETHER. 



M. Pelouze obtained this compound by the action of heat upon a 

 mixture of sulphovinate of barytes and cyanuret of potassium. This 

 aether is colourless ; has a strong alliaceous smell, is extremely dele- 

 terious to the animal ceconomy; inflammable j boils at 1 76° Fahr. ; 

 its density is 0787 ; is very slightly soluble in water, but combines 

 with alcohol and sulphuric aether in all proportions. It does not pre- 

 cipitate nitrate of silver ; in which respect it resembles muriatic aether, 

 which does not decompose this salt until it has been previously de- 

 stroyed by the action of heat. 



Hydrocyanic aether is formed of equal volumes of olefiant gas and 

 cyanogen, condensed to one half : this is indicated by direct analysis 

 and the density of its vapour. — lbid. t p. 486. 



DISTILLATION OF TARTARIC AND PYROTARTARIC ACIDS. 



M. Pelouze finds that tartaric acid, like other vegetable acids, 

 yields very different products, and in very variable quantity, according 

 to the temperature employed in its distillation. 



With a naked fire there are obtained empyreumatic oil, olefiant 

 gas, water, carbonic acid, acetic acid almost crystallizable on account 

 of its great concentration, and a quantity of pyrotartaric acid so 

 small and so mixed with other products that it is difficult to separate 

 it. From about 400° to 570° Fahr. the same products are obtained, 

 but in very different proportions, and the pyrotartaric acid is much 

 more abundant: between 350° and 375° the proportions of pyrotar- 

 taric acid and acetic acid increase still more than the traces of empy- 

 reumatic oil j but there are sensible quantities of acetic [carbonic ?] 

 acid, carburetted hydrogen, and carbon. By evaporating the product 

 of this distillation crystals are obtained, which it is possible to purify, 

 but by a long and delicate operation. The following is the best 

 process : 



Put the compound liquid in which the pyrotartaric acid is dissolved 

 into a glass retort, and distil until the residue has acquired a syrupy 

 consistence ; then change the receiver, and continue the distillation 

 to dryness ; expose the liquor last distilled to a very low temperature, 

 or to spontaneous evaporation in vacuo. In both cases irregular yel- 



