334 Scientific Newsy Accounts of Books, &c. 



Decompofttion of the fixed Alkalis, 



Van Mons, in a Letter to C. de la Metherie, inferted in the Journal de Phyfique, 

 Vol. VII. p. 390, acquaints him, that Craaiier, an apothecary at Amfterdam, has made 

 an experiment, by which it appears that the alkalis contain carbon. He includes pot-alh, 

 or foda, moiftened with water under an inverted glafs with oxygen gas. The gas is ab- 

 forbed, and the alkali becomes eftervefcent. Moreover, he finds that an alkali, treated a 

 certain number of times [quelquefois) with this gas, becomes exhaufted of carbon, and 

 can no longer be made effervefcent. 



V. M. long ago publilhed, that pot-a(h is formed during the combuftion of hydro- 

 carbon, and during the fermentation of grapes, by the intervention of the azote of the 

 atmofphere. He adds, that when thefe operations are made in pure oxygen, neither pot- 

 alh, nor the acidulous tartrite of that alkali are obtained ; but the wine becomes too four 

 to be drank. He conjectures, that the fixed alkali may be carbonated azote. 



But he mentions two experiments which militate againft this theory. In the firft he 

 expofed cauftic pot-afli, and the red oxide of mercury by fire, to red heat in a retort, and 

 obtained nothing but oxygen gas, nitric acid and water. In the fecond, he triturated the 

 oxymuriate of pot-afh with cryftals of cauftic alkali, and poured the mixture into a phial, 

 which he kept exadtly clofed for three days. At the end of this period he poured muriatic 

 acid upon it, but had no efFervefcence. 



As carbon is not combuftible in the air but at a red heat, our author remarks, that if 

 this principle enter into the compofition of alkalis, it muft be united with hydrogen, unlefs 

 azote ferves as the medium of its union with oxygen. 



In the fame Journal for Meflidor VIII. I find a note, page 82, in which it is aflerted, 

 that Guyton Morveau, on the 6th floreal, read to the French National Inftitute a memoir 

 on the conftituent principles of the fixed alkalis. He made his experiments jointly with 

 Deformes pupil of the polytechnic fchool, and their conclufions are, 



1 . That pot-a(h is compofed of lime and hydrogen. 



2. That foda is compofed of magnefia and hydrogen. 



3. That lime is compofed of carbon, azote, and hydrogen. 



4. That magnefia is compofed of lime and azote, and confequently of carbon, hydrogen, 

 and azote. 



Separation of Butter. 

 BrugnatcllI has feparated butter from cream without the afiiftance of oxygen. He 

 pours four parts of hot water to one of cream, and pafles the mixture through a ftrainer of 

 coarfe cloth in a clofed veflel, in which feveral ftrainers of the fame kind are ftretched. In 

 twenty-four hours the whey has pafled the ftrainers, and the butter is perfedly feparated. 



J. dc Phys. VII. 391. 

 Beet 



