ON THE PURITY OF THE FIXED ALKALIS. 33 



carbonate, which I had prepared, was conducted with all subcarbonate 

 posbible cf»re, varied in several waj's, and ucitbrraly an- ° ^° *** 

 uounced its conipositioa to be 



V/ater 63.61 



Carbonic acid l6'04 



Soda 20-35 



100. 



Considering- myself certain of the accuracy of thtse re* 

 fcults, ail J having paid so much the more attention to the 

 *.'Xperiments tuat furnished them, because they were to serve 

 as a standard to the rest, I thought I might take this ana- 

 lysis as a seUled point, and tliea proceeded to the following 

 experiments. 



Taking- the u^rul precautions, I first neutralized 100 gr. Quantity of 

 fl544 trrs] ol' il.c subcarbonate of soda abovementioned. sulphuric aciA 



*■ V . . . required to 



Repeating- this experiment several times, the mean term of saturate it. 



the results wai. 347, expressing the quantity of diluted acid 



required for the saturation, and representing 34-7 grammes 



of concentrated acid. 



Thus I found myself authorized to conclude, that the: 

 employment of 34*7 grammes of concentrated sulphuric 

 acid, similar to that of which I have given the specific 

 gravity above, would always represent, at the same tem- 

 perature, in a solution of soda brought by this acid to the 

 neutral state, 100 grammes of subcarbonate of soda similir 

 to that I had analysed; or, which is the same thing, 36-39 

 of dry subcarbonate, or 20*35 of pure soda. 



I then repeated the same experiments, substituting, in- Soda purified 



stead of the subcarbonate of soda, caustic soda prepared ^^*^^ alcohol 



^ ^ saturated witD. 



with alcohol, hitherto considered as pure soda, and the real the same aoid-s 

 standard of this alkali : but I was surprised at the results i 

 obtained; and the conclusions 1 was compelled to draw ap- 

 peared to me so contrary to the received opinions, that I 

 omitted nothing, to remove every sort of doubt. Accord- 

 ingly I made a number of experiments, and obtained the 

 following results. 



First I examined four diiferent specimens of soda pre- 

 pared with alcohol, and simply fused in a silver capsule; 



Vol. XXYII.—Sept. 1810. D none 



