The AffinttUs oftvUkh (he Earths exert upon each others £?c. 483 



ir. 



New Refearches into the Affinities of which the Earths exert upon each other in the humid 



and dry Way, By Citizen Guyton. 



B- 



(Concluded from page 422.) 

 Experiment 16. 



>ARYTES and ftrontian, In the fame circumftances, fliewed nodifpofition to unite. 



Experiment 17. Strontian was prcfcnted to aluminc by means of the fame folvent. 

 The mixture aflumed a milky colour, and afforded a precipitate, which the acid dijl 

 not redlffolve. 



In fupport of thefe experiments, I may refer to thofe of Citizen Vauquelin, in which he 

 has fliown the aftion of barytcs and ftrontian upon alumine *. This property is here afferted 

 only in the due humid way as well as with regard to lime. They do not determine the 

 vitrification of aluminc. My experiments on this fubje£l perfeftly agree with thofc of 

 Macquer, Ehrman, Achard, and Ktrwan f . 



We are indebted to the illuftrious Scheele, in his Diflertation upon Quartz, Alumine, and 

 Lime J, for the flrft obfcrvation refpe£ting the combination df alumine and lime. I have 

 repeated the experiment which proved to him the poffibility of this union, and I obferved, 

 as he did, that the produfl was a peculiar kind of earth, compofed of alumine and lime, 

 when alum was decompofed by a more confiderable quantity of lime water than was 

 rreceffary to precipitate the whole of the alumine. 



The confequences to be drawn from thefe experiments naturally prefent themfelves. 

 Two earths held in folution by the fame fluid, water for example, if they be foluble in that 

 fluid or alkali if this folvent be neceflary, or otherwife in one and the fame acid. Thefe ex- 

 crcife a mutual ■aftion, which tends to unite them, and feparate them from the folvent, 

 which, according to the laws of elective attraftion, is effe£lual with regard to fome earths, 

 and ineffe6bual with others. 



Thus it is, for example, that in the i, 5, 10, Jith experiments> barytes and ftrontian 

 a£l -very differently with lime. A confiderable refemblance in the refults of the fame earths 

 in different folvents, may alfo be remarked. Lnftly, in the loth experiment upon the earthy 

 muriates, there are only four in which the mixtures did not give manifeft tokens of the 

 divellent affinities ; and it may perhaps be proper to exclude from the lift of exceptions the 

 rhurrates of magnefia aftd alumine, which conftantly affumed a milky tinge. 



It muft not however be concluded, that no affinity exifts where there is no decompofi- 

 tion, or that it cannot even prove divellent in fuch cafes ; "that is to fay, by changing the 



• Annales de Chimk, XXIX. ^70, or Philof. Journal, HI, ijii. 



f See the Journal Polytechnique. Cah. 3. p. 307, and Kirvvan's Mineralogy, I. 56* 



X See the French edition of his -Effays, p. 96, fcc; 



commoa 



