268. Jntelligencg and Miscellatieoiis Articles. 



. The properties of butyrone are, that it is a colourless limpid liquid^ 

 possessing a strong peculiar odour and a burning taste ; its density 

 is 0*83, and it boils at about 290° ; -when submitted to cold produced 

 by solid carbonic acid and aether, it becomes a crystalline mass. It 

 floats on the surface of water, in which it appears to be nearly inso- 

 luble, although it imparts its odour to it ; it mixes with alcohol in 

 all proportions ; it is readily inflammable and burns with a bright 

 flame. The action of chromic acid on butyrone is extremely vivid, 

 it burns as soon as they come into contact j it does not acquire colour 

 by exposure to the air, although it eventually absorbs a considerable 

 quantity of oxygen. 



Several analyses of this substance gave similar results, which indi- 

 cated as its formula C' H^O ; the density of the vapour confirms this 

 formula. Experiment gave the number 4"0, very near the theoretic 

 number 3" 9 6. The formula C' H^ O therefore represents two volumes 

 of the vapour of butyrone. 



This composition sufficiently explains the formation of this sub- 

 stance ; butyrate of lime, submitted to distillation, is decomposed 

 into carbonic acid, which remains combined with the base ; and in 

 butyrone, which distils, this is shown by the following equation ; — 



CaO, C8H708 = CaO, CO^ + C^H^O. 



Butyrate of lime. Carb. of lime. Butyrone. 

 Thus the dry distillation of butyrate of lime is not less perfect than 

 that of the acetate of the same base ; the decomposition takes place 

 readily, and the quantity of butyrone obtained under proper circum- 

 stances agrees with the indications of theory. — Ann. de Ch. et de 

 Phys., October 1844. 



POTASH AND OXIDE OF CHROMIUM. BY M. FREMY. 



Hydrated oxide of chromium dissolves in the alkalies and forms a 

 green solution, which has the same green colour as the salts of chro- 

 mium. The author could not succeed in obtaining definite com- 

 pounds of oxide of chromium and an alkali, owing to the extreme 

 instability of these compounds ; the history of the compounds of oxide 

 of chromium with bases may be reduced to the following facts : — 



Oxide of chromium, like that of zinc, dissolves only in the alkalies 

 when it is hydrated ; when anhydrous it is insoluble in alkaline so- 

 lutions ; when oxide of chromium combined with an alkali is dehy- 

 drated, it immediately quits the base and is precipitated ; so that 

 when oxide of chromium is dissolved in potash, the solution remains 

 bright while it is not heated, but if boiled the metallic oxide is de- 

 hydrated by the action of the potash and is precipitated ; if also a 

 solution of oxide of chromium in potash be evaporated in vacuo, it is 

 decomposed, and the effect is more rapid when the solution is strongly 

 alkaline ; these effects are produced upon several oxides soluble in 

 the alkalies. When potash and oxide of chromium are calcined 

 together in a silver crucible, the oxide absorbs oxygen and a chromate 

 is formed. 



