37°" New Publications. 



at reft for twenty-four hours, to favour the feparation of the 

 mucilage ; then filter it through paper, and faturate it with 

 a quantity of the carbonate of lime. The citrate of lime, 

 ■which refults from this faturation, being infoluble, is preci- 

 pitated to the bottom of the liquor : when this depofit is well 

 formed, draw off the fupernatant liquor, and wafh the preci- 

 pitate until i f becomes infipid and exceedingly white ; then 

 decompofe this fait by the help of a gentle heat, with half its 

 weight of fulphuric acid, diluted with fix parts of water; the 

 fulphuric acid takes the lime from the citric acid; the greater 

 part of the fulphate of lime formed is precipitated, and the 

 citric acid remains free in the water. This acid may be 

 obtained under a cryfialline form, by evaporating it to the 

 confidence of clear fyrup, and then fuftering it to cool. 



Dize, who made feveral experiments on this fubje£l, found 

 that an excefs of fulphuric acid was neceffarv to deftroy the 

 portion of mucilage, which the acid obftinately retains in its 

 combination with the lime, and which oppofes its cryflalli- 

 zation. He obferved alio, that to obtain the citric acid per- 

 fectly pure, it was neceflary to diflblve it, and to caufe it to 

 cryfiallize feveral times. 



The cryftals obtained by Dize were rhomboidal prifrns, 

 having their planes inclined to each other at angles of about 

 60 or 120 degrees, and terminated on each fide by fummits 

 vyith four faces, which intercepted the folid angles. 



One part of diftilled water at the temperature of ten de- 

 grees, according to this author, diflblves 1-25 of cryltallized 

 citric acid, and, during the folution, cold equal to 1$ degrees 

 (29° F.) is produced. 



This acjd reddens blue vegetable colours : when expofed 

 to the lire in dole veflels, with a pneumatic apparatus, it is. 

 decompofed ; an acid phlegm, carbonic acid gas, and carbo- 

 nated hydrogen gas, are obtained from it : and a little char- 

 coal remains. 



Its cryfials effiorefce in the air. 



An agreeable lemonade may be prepared with this acid : 

 for this purpofe Dize propofes about half a dram of the acid 

 diflblved in about two pounds of water, and a furhcient 

 quantity of fncrar and cleofaccbai-um. made with lemon peel. 



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