300 M. H, Rose on Boracic jEther, 



This method of preparing anhydrous benzoic acid has the advan- 

 tage over the original method of Gcrhardt, that the material 

 chloride of sulpliur is cheaper and more easily pi^^fiTi^ ^fe^ .ft© 

 pentachloride and oxychloridc of phosphorus. , ,,|., .fif^f ^ ,}:[ * 



h'»Heinrich Rose* obtained boracic ajther by distilling together 

 a mixture of sulphovinate of potash with excess of fused boracic 

 acid. At a temperature of 100° to 120° C, a colourless mobile 

 liquid, of a strong setherial odour, passes over, having all the 

 properties ascribed to boracic tether by its discoverer. If, in 

 the preparation of this body, anhydrous materials be not em- 

 ployed, water passes over with the distillate and gradually de- 

 composes the aether, boracic acid being liberated, -^nouimi^ m 



The analysis of the sether was made in the following 'maii'rlfeH—r 

 A weighed quantity, 0-967 grm., of the sether was left in a closed 

 vessel in contact with water for many days. It was then eva- 

 porated to dryness with a weighed quantity, 2*180 grms., of car- 

 bonate of soda; the mass gently ignited and weighed. It 

 weighed 2*260 grms. The carbonic acid contained in this was 

 determined ; it amounted to 0*736 grm., and hence the boracic 

 acid was 0*246 grm., or 25*44 per cent., the theoretical number 

 being 24 per cent. Ebelmen, the discoverer, found 22*3 per 

 cent., but the method of analysis employed by him involved a 

 loss. >'-<^'- 



})' Rose attempted by the same method to produce from silicate 

 of soda, and carbonates and phosphates of the alkalies, the cor- 

 responding silicic, carbonic, and phosphoric aethers, but in vain. 

 Equally unsuccessful were similar attempts to form from bichro- 

 mate and from molybdate of potash their respective aethers. 



No aluminic aether was obtained by distilling pure aluminate 

 of soda (prepared by heating together atomic weights of alumina 

 and carbonate of soda) with sulphovinate of potash. Nor by the 

 action of chloride. of, aluminium .on.alcohoIwa^ a more farourabl/e 

 result arrived at. ^ . r raiirrT/r . \r\ xr j *^ 



^ Wilkens f has an article on artificial ultramarine, in which he 

 Adverts to the views put forth by Stolzel % on the constitution 

 of this body. Wilkens considers that in artificial ultramarine a 

 certain constant compound is contained, but mixed with other 

 foreign bodies. Resting on a number of careful analyses, as 

 well as on its reactions and properties, he considers blue ultra- 

 marine to have the formula — 



'^, 2(AP03 SiO^) + AP03 3Si03 + NaO S202 + 3NaS. ^no-ria 



The formula which Wilkens derives from his analyses is different 



* Poggendorff*8 Annalen, Jva^ii . »njiT. .>^f.M .firf^ * 

 ; ;t Liebig*8 Annalen, July. ' ' -f Phfl. Ma^."J\irie. 



