J 44 '^" ^^^ Analyjis and Synthejis 



made bv mixing a folution of muriate of ftronttan with a fo~ 

 lution of muriate of alumme. According to his account) the 

 liquor affumed a milky colour, and gave a precipitate which 

 the acid did not redifiblve. This experiment, repeated, like 

 all the reft, with a great deal of care, ftill confirmed the pre- 

 fence of the fulphuric acid in the folution of muriate of am- 

 monia he employed ; for I had no precipitate when I repeated 

 the experiment, and the liquor, for five months, loft nothing 

 of its tranfparency. 



By admitting between earthy fubftances an affinity of 

 which nature affords a thoufand examples, I do not however 

 think that the force which attrafts them is fufficiently great 

 to make them abandon their folvent, without evaporation, 

 efpecially if it be acid. There is none indeed but filcx dif- 

 folved in alkali that has the property of precipitating the 

 other alkaline earths from their aqueous folulions: the other 

 earths produce nothing of the kind; for, if alumine diflolved 

 in an alkali be mixed with folutions of barytes, ftrontian, 

 lime, &c. no precipitate will be formed ; nothing more will 

 take place between the ftrontian, lime, barytes, &c. 



If the experiments of Guyton had really eftablifticd the 

 fa£ls he announces, we Ihould have had no longer any cer- 

 tain means for analyfing earths and ftones^ and every thing 

 hitherto done on this fubjeft could only have been confidcred 

 as fo many incorreft refults. 



I therefore think myfelf authorized to conclude, from the 

 fafts announced in this memoir, that the pha;nomena ob- 

 ferved by Guyton were occafioned in many cafes by foreign 

 bodies contained in the matters he employed. 



LVI. Experiments concerning the Analyjis and Synlhefis of 

 Alkalies and Earths, announced by C. GuYTON and 

 Desormes. By C. DARRACa, Pupil of and AJJiJiayit 

 to C. Vauquelin at the School of Mines *, 



A HE third volume of the Memoirs of the Tnftitute of 

 France contains fome experiments by C. Guyton and Des- 

 ormes on the compofition and decompofition of the two 

 fixed alkalies, and iome of the earths fuppofed to be fimple. 

 The importance of fuch difcovcries, the period of their being 

 made, and their utility to the arts, invite all chemifts to re- 

 peat them; and fuch were the motives by which I was guided 

 hi my refearches. To announce that my experiments were 



* piom the Annates de Cbimie, No. iig- 



made 



