H4 Rtfiarcbes rcfpe&lng the 



juice at the fame degree of confidence, and with the fame 

 colour; a^d though it has loft the mucilage it cannot be 5 

 yet rendered cryftallizable by concentration, becaufe its ex- 

 tractive matter, foluble in water, remains in it. The juice 

 employed in theie experiments gave about five or fix degrees 

 of Baume's areometer. When dried as much as poifible, 

 without altering it, it produced 48 grains per ounce of dry 

 matter. 



V. Four ounces of white chalk were expofcd to heatywith 

 a pound of water, in a filver bafon. It was afterwards fatu- 

 rated by pouring lemon iuice fucceffively into it as long as 

 an effervefcence was produced. When this point was ob- 

 tained, about an ounce of juice Was added, in order to be 

 certain that the earth was completely faturated. For this 

 procefs 94 ounces were required. 



When the mixture had cooled it was decanted from off 

 the citrate, which occupied the bottom of the bafon. It was 

 then waihed three or four times with cold water in order to- 

 feparate all the remainder of extractive matter, and there 

 were obtained by thefe means feven ounces and half a dram 

 of white calcareous citrate, pulverized and light. 



The liquid feparated from the citrate added to the water 

 employed in the warning was evaporated to a certain pointy 

 bv which means there were obtained alfo 3^ drams. The 

 product of the citrate was confequently 7 ounces 4 drams ; 

 and by adding half a dram, which, according to my eftima- 

 tion, remained in the extract of the. liquids evaporated, there 

 were obtained altogether 60 drams and a half of this citric fait. 



VI. As the citric acid, by uniting with the chalk, expelled 

 the carbonic acid, the queftion now is to know the amount 

 of the latter, in order to afcertain the quantity of the citric 

 acid which replaced it. 



Analyjis of tins Chalk. 

 A hundred parts, converted into lime by calcination, 

 were reduced to 56^. The lofs of acid and water was there- 

 fore 43 J per cent. A hundred parts of the fame chalk, dif- 

 folved by nitric acid, loft only from 40 to 41 of carbonic 

 acid. Confequently, there is about three per cent, of water 

 in this earth. The nitric acid feparated alio about three of 

 argil {lightly ferruginous. The quintal of chalk may then 

 furnifli the following refult : 



Argil 3 



Water 3 



Carbonic acid - 40^- 



Lime - - 53^- 



Total jtoo 



In 



