Quarterly Abstract of European Chemistry. 189 



Class of double Sulphates containing Soda and a Magnesian Oxide, 

 (Lon. and Ed. Phil. Mag. July, 1844, p. 502.)— These double salts are 

 formed without any difficulty, by dissolving the salts together in equiv- 

 alent proportions and evaporating at a temperature of 130° F. ; below 

 this temperature the sulphate of soda is apt to separate by itself. In 

 this way the double salts of sulphate of soda, with magnesia, zinc, 

 iron, copper, and manganese, have been formed. 



Boracic Ether, by M. Ebelman, (Compt. Rend. June, 1844, p. 1202.) 

 — When equal weights of fused boracic acid (pulverized) and absolute 

 alcohol are mixed, considerable heat is disengaged, and upon attempt- 

 ing to drive off the alcohol by heat, it will be found that it is necessary 

 to raise the temperature much above the point of ebullition of alcohol 

 before all the liquid disappears. Stopping the distillation at about 

 110° C. (230° Fah.) and treating the mass left when cold with anhy- 

 drous ether, decanting the ethereal solution, and evaporating by heating 

 progressively up to 200° C. (392° Fah.) there remains a viscid liquid 

 which at this temperature affords white fumes, and solidifies on cooling. 

 This is boracic ether. It has a feeble ethereal odor, and a burning taste ; 

 placed upon the skin it produces a sensible impression of heat ; subject- 

 ed to the action of heat, it decomposes at 300° C. (572° Fah.) with the 

 formation of olefiant gas. This mode of the decomposition of boracic 

 ether affords a method of preparing olefiant gas with ease ; for by heat- 

 ing together 3 parts of fused boracic acid (pulverized) with one of ab- 

 solute alcohol, a regular and abundant flow of gas is obtained without 

 the formation of carbonaceous matter. The analysis of boracic ether 

 gives BO^ C^H^O. The action of boracic acid upon pyroligneous 

 spirits is of a similar nature to that it exercises upon alcohol. 



The Sulphate of Chrome, by M. E. Kopp, (Compt. Rend. June, 1844, 

 p. 1156.) — The observations made connected with the compound are 

 of some interest; it is composed as already known of 380^ Cr^ O^. 

 By adding repeated portions of bichromate of potash to sulphuric acid, 

 heated nearly to the boiling point, it is formed with a disengagement of 

 oxygen gas ; tlie chromate is completely decomposed ; and if the mass 

 be treated with water, the excess of acid with the bisulphate of potash 

 is dissolved, but no trace of any chromic salt. And this fact has 

 suggested to the author the possibility of using this as a means of 

 separating chrome from other ingredients ; for by heating a mixture of 

 iron, alumina, zinc, chrome, &c. with an. excess of sulphuric acid, 

 and concentrating the liquid, the chrome will separate in the form of 

 the insoluble sulphate. It is a green powder ; heated it becomes of a 

 rose color, but upon cooling returns to its primitive hue. The action 



