ftUiiNTIT^Y., OP- WATBft JN FUSED SODr.V, • ^d*^ 



J .f , ,. 111. - , -, '\- ■ i:-'[: .r.:.i 



Ntf^loHi^d: Water eontained in fmed Soda. By Mi'. J, 



JMLR.' d'Arcct had found, that pure alkalis, after being Water in soiTa 

 fuscdy CQiitained water, and he estimated the quantity *"^''^"^'°"' 

 ini sqd.a as Wgh as 28 percent f. An analysis, which I 

 made SQtQe time after in a ditferent mode, gave me but 



is-sel . 



Tbfr res,ult of Mr. d'Arcet is founded on the analysis of ^fr. d'Arcct 



the subcarbonate of soda. For this salt too he has given ^'l^- ^'^*^ff''"\ 



■ _ i5 portions of sub- 



proportions different from those I found j;. Not know- carbonate of 



iiig the particulars of Mr. d'Areet's experiments, I ascribed j"otti!l''''^"^ 



the difference of our results respecting the water in soda author, 



to the difference in these proportions. In confirmation of 



his opinion however, he has just published these experi- ^ 



m^ents; and has made several objections to my method of ^nd makes 



analysing, the subcarbonate, which I shall endeavour to'° ^'^ "^^^^''"'^ 



remove. 



:,He considers the solution in acids as an iaaccurate mode; tw6 objectloriit:'"^ 

 1st, because the solution retains carbonic acid : 2dly, be- ^^^*^ 



cause the gas evolved carries off water with it. cnsv o» La 



It may be observed, that, -these sources of errour being Tlie^e crmnrs 

 opposite Jnt their effects, they- in gr^at measure counteract*^"'' ^"^^^'^^nce 

 each other: but we shall see what is their extent. TheThe'first'must 

 temperature amounts at most to 20* [68'-'F], when the*^*^"/ ^'^^y 

 carbonate decomposed by the acid is already in solution. ' *• "^ ' • 

 Now at this temperature water under the pressure of the 

 atmosphere alone would not dissolve any thing like its 

 owji bulk of carbonic acid gas. But this quantity may 

 be wholly neglected, when we considf^r, that a large ex- 

 csifB of ^sulphuric acid is added, and the solution strongly 

 s}t4kien>?;..l . 



i:7.s ,. ^.* 'i:^ ■', . , -. 



* Annales dc Chim. vol. ixxii, p. 90. 



t Ann.'de Chim. vol. Ixviii, p. 17.5; or Journal, p. 31 of the' 

 present vol. 



^ X For the compofient parts of different salts by Mr. Bcrard sec 

 Jourial, vol, xxvi, p. 20C, 



As 



