240 ON SALTS. 



leaves to the buds in (be fubfequent growth of the tree; and 

 I am in potfeffion of many facts to prove that feedling trees, 

 in the flrfl ftage of their exigence, depend entirely on the 

 nutriment aflbrde I by the cotyledons; and that they are 

 greatly injured, and in many inftances killed, by being put to 

 vegetate in rich mould. 



(To be concluded in the Supplement.) 



III. 



On the Deliquefcence and Efflorefence of Salts, Bj/CL.C\ det.* 



Deliquefcence ilLL chemifts are of the fame opinion relative to the caufe 

 a ndtfflorefeence of t})e deliquefcence or the efflorefcence of a fait. The at- 

 are occanoned by /T\ ■» 



the relative at- traction of the fait for the water contained in the atmofphere 



traclions'of the occafions the fir ft phenomenon, the attraction of the atmof- 

 air and of each . . . , - , 



felt for water, pneric air tor the water of cryitallization or the lalt caules the 



fecond. 

 The difference This attraction has been found to vary in the different falts, 

 between one fait wne ther deliquefcent or efflorefcent, to be ftronger in fome 



and another has i > ,. , ' , , ,/• 



been noticed, kinds, and more Ipeedy in others; but no one has yet obterved 



but not the va- whether it had any dependence on the constitution of the at- 

 xiations from the r . , , _ . „ c . , r . . 



ftate of the air, motphere, the electric Hate or the air, the quantity ot caloric 



&c. it contained, if it was always the fame in any one fait, and if 



it regularly became weaker in proportion as faturation ap- 

 proached, neither have any tables been, yet prepared, which 

 might indicate the degree of deliquefcence, or of efflorefcence 

 of the different falts. 



Of the hypothefes which could be made on thefe pheno- 

 mena, the following feemed moft probable. 

 Hypothefes that The falts which deprived the air of its humidity ought to 

 ftoukTlttraa* 118 a6t in this rer P e & in proportion to the quantity of water which 

 water in propor- the air held in folution or in fufpenilon. The greater the no- 

 tion as the hy- midity of the air, the more fhould the deliquefcent falts aug- 



grometer indi- -. »-,•>'« , , r , • •,«,., 



cated its pre- ment in weight, to that the degree or their weight fhould be 



fcnee. conformable to the 'progrefs of the hygrometer. 



Barometrical On the other hand atmofpheric preffure, which more or lefs 



c anges an oppofes evaporation, ought to have an influence on thefatura- 



* Journal de Phyficrue, LX* 



tionv 



