S50 On the Alkalies of Commerce. 



the left side, and runs from bottom to top. The en^trcir- 

 ing (Plate IV'.) will explain this two-fold arrangement. 

 The BerthoHi-meter by this iiK-ans is much simpler than it 

 was- when I gave the first description of it. I should, in- 

 deed, mention that the new Berlholli-mcter has not the same 

 precision as the first. As it is, however, it cannot fail to 

 be very useful tu bleachers after the Berthollian process. I 

 take pleasure in rendering this new homage to a chemist so 

 celebrated, and to whom we owe an art from which com- 

 merce in general, and that of Rouen in particular, has de- 

 rived immense advantages *. 



Constant Proporttons rf Carlmiic Acid in the Salt iiith 

 Excess of Base, ivliick is extracted from all tiie Ashes. 



Of all the acids combined with the alkalies the carbonic 

 acid is that w hich deprives them tlie least of their cnergv, 

 and which may be tj.kcn from them wiih most facility ; it 

 is by means of lime that, from time inmiemorial, the effect 

 has been produced upon which several chemical arts have been 

 founded, and jiarticularly that of the soap-makers; but, as the 

 existence of carbonic acid was scarcely known formerly, the 

 art of consbining it with lime, by taking it from the alkalies, 

 is felt even at the present time, as a consequence of the an- 

 tient imperfection of chemical knowlcdee. Although for 

 more than five-and-twemy years tlie theory of the various 

 carbonates seems to leave nothing more to be desired, I may 

 venture to say that we have not even yet any certain rules 

 for the cautuiiication of the alkalies by lime. 



I shall only announce at present, that numerous observa- 

 tions have proved to my brother and myself, that the potash 

 furnished by the combustion of all 'the vegetables is a salt 

 \\.ith excess of base, in which the proportions of carbonic 



' I intend to publish, sImo<it imiiiediately, a memoir relative to the applica- 

 tJan of the alliah-metric;;! tube to proving- the acetic, pyro-acctic, oxah'c, and 

 tartarous acids, &c. It will only he rei]ui',itc to substitute in place of the 

 mixtare of sulphuric acitl and water, an alkiiliiie solution of a [(wen alkali- 

 ncti-ical degree, and alio to submit to trial a given weight of these acids with 

 a vegetable base. The Ktter will probRbly one day act a very important part 

 in the arts, and it will be important to be al.lc to asccrtnin their energy easily, 

 m ofder to be on our guard against the sophistications oi »*^c dealers. 



acid 



