Intelligence and Miscellaneous Articles. 397 



which are to be separated by filtering paper, washed with cold water, 

 and then strongly pressed between folds of filtering paper. They are 

 then to be dissolved and boiled in a solution of hypochlorite of soda 

 to decolorize them, and the solution is to be decomposed by gradually 

 adding hydrochloric acid. The opianic acid usually crystallizes in a 

 colourless state on the cooling of the liquid ; after washing it with 

 cold water, the acid is to be again pressed and purified by repeated 

 crystallizations. 



The liquor from which the crystals are originally obtained is to 

 be treated afresh with sulphuric acid and manganese to obtain more 

 of the acid. — Ann. de Ch. et de Phys., Octobre 1844. 



ON SILICIC iETHERS. BY M. EBELMEN. 



The author has procured two definite combinations of sether with 

 silica, by means of the action of absolute alcohol on chloride of sili- 

 cium ; the circumstances under which they are produced are the fol- 

 lowing : — 



Cautiously pour absolute alcohol into chloride of silicium, and a 

 vivid reaction takes place with a very abundant disengagement of 

 hydrochloric acid gas, and a considerable reduction of temperature ; 

 when the weight of the alcohol added rather exceeds that of the 

 chloride of silicium, no further disengagement of gas is perceived, and 

 the liquor becomes very sensibly warm. If it be submitted to distil- 

 lation, there first passes ovjr a certain quantity of hydrochloric aether, 

 and then the greater part ■j'^ the liquid contained in the retort distils 

 between 320° and 340° F. ; the latter product is to be set aside and 

 the distillation is to be continued until it terminates at above 570° 

 F. ; there remains a mere trace of silica in the retort. 



The product distilled between 320° and 338° was rectified until 

 its boiling point became fixed between 323° and 325° ; by this there 

 was obtained a colourless liquid, possessing a penetrating and sethe- 

 real odour, a strong hot taste, and its density was 0*932. Water 

 does not dissolve it, and decomposes it very slowly with a deposit of 

 silica ; it is perfectly neutral to test papers ; alcohol and sether dis- 

 solve it in all proportions ; the alcoholic solutions of the alkalies de- 

 compose it rapidly, and by means of acids, silica is separated in the 

 gelatinous state. When a few drops are thrown upon red hot platina, 

 they burn with a white flame, depositing silica in the state of an im- 

 palpable powder. 



The analyses of this compound show that it contains carbon and 

 hydrogen in the same proportions as in aether, and that the silica 

 contains the same quantity of oxygen as the base. 



If then 277*32 be admitted as the equivalent of silicium, as allowed 

 by most chemists, and SiO^ for the formula of silica, that of the 

 aether will be Si0^3C*H.'0. If, on the other hand, we take the 

 third of the preceding number, or 92*44, as the equivalent of silicium, 

 and SiO as the formula for silica, as proposed by M. Dumas, accord- 

 ing to the density of the vapour of chloride of silicium, the formula 

 for silicic aether will be similar to that of other compound aethers, 

 and represented by SiOC^H^O. 



