1825.] Sdemijk M^M'^Ch^j^sif^^^^^^^^^ S#t 



• V iiA.RTICLE XIII. i. A t* 



.V * Bofi|igiFIC NOTICE^.^^ 



^ ," . Chemistry. 



] , Reciprocal Action of Hydrosalphuric {Sulphuretted Hydrogen) 

 and Carbonic Acid, qu the Ca^i^bq^iate^s^^j^nd Hydro^ulp^^s, 

 By M. Henry, Jun. ^ " ! '" qgorai^ 



Althougi^L M. Chevreul had shown that carbonic acid ii^i 

 capable of decomposing the hydrosulphates, {hydrosulphurets,) 

 yet when Mi Henry advanced the opinion that the sulphuretted 

 hydrogen disengaged from the mineral waters of Enghien, is 

 owing to the action of free carbonic on the hydrosulphates con- 

 tained in those waters, it met with considerable opposition, in 

 consequence of which he resumed the subject, and undertook 

 a series of experiments with a view to elucidate it ; from whichi 

 he has deduced the following conclusions : 



1. Carbonic acid, in contact with the alcaline, or magnesian 

 hydrosulphates, is capable of decomposing them <Jonipletely, if 

 the action be continued for a sufficient length of tim€. 



2. The decomposition is effected either by boiling a h^drcr*- 

 sulphate in water impregnated with carbonic acid, or by placing 

 the mixture, without heat, in the vacuum of an air-]Dump ; or by 

 passing a current of carbonic aci^^as,, through a,'.diJjU.t^^.§QJLM- 

 tion of the hydrosulphate. [j ^lu^? mo b isbnis sd 



3. The hydrosulphates obtained cty converting §^^hftjbp%itot|:^ 

 Bulphurets, by carbonaceous matter, are less readi|y;jg,|:^e§tfg)niiGff^ 



4. The result of the decomposition of all these salts is the 

 production of carbonates, or rather of bicarbonates, and the 

 quantity of sulphuretted hydrogen disengaged is proportionate^ 

 to^th^tjigjilk^,smb.m^t& formed.— (BuiletigA^oSGie,»C]eft.).i. i 



'On^Jgib 9rii ol !x;qoii- __ , ., ^^wjoIIoI 8b bnuol sd 



-'imoiB 3di ^ 2, Larhono- Phosphate of So^-^^ ^^^ rrsawlad 



i(ffibw3«4^ a Prussian blue manufactory in ttoiMa^bDatdiooS) 

 of//Ql8i^sgow belonging to Mr. Macintosh, in' whichy[liMew4s^ 

 prussiate of potash is made in very considerable quantities. The 

 acid is obtained by the combustion of the hoofs of bldfel^liartfl^ 

 imported chiefly from Ireland ; and the hoofs of a thousand 

 cattle are required for every day's consumption in the 'tnmiiiiS,i> 

 tory. The slaughtering of cattle in Ireland having considerably 

 diminished at the end of the last war, hoofs became scarce. 

 This induced Mr. Macintosh to substitute the animal substance 

 caW^d' cracknales, procured chiefly, I believe, from thfe' San^le^ 

 makers. Soon after this substitution, considerable quaptitjgj^g^ 

 a 'white salt in fine needles began to make their appearance ,^ftr 

 the prussiate of potash leys, and incommoded the process con- 

 siderably. These crystals exhibiting appearances different from 



