IS4, 



RECTrHCATION OF NITRIC ACID. 



mother-water of the firft cryflallizalion, which isalraoft wholly 

 muriate of liliie, is to be let afide for a frefli operation, or for 

 any other purpofe. 



As the infolubie mafs of fulphate of lime ftill contains a 

 l^rge quantity of fulphate of barytes, indeed about half the 

 original quantity, it is to be treated afreth as above, with one 

 fourUi.part of muriate of lime; and the fame procefs is to 

 be repeated with an eighth pan of the fame fait. Thus we 

 obtain an addition from one to two eighth parts of muriate of 

 The fait to be barytes. The falts of the various cryilallizations require to be 

 cryftallization' ^^^"^^^ed and re-cryftallized anew, in order to free them from 

 a Jittle muriate of lime, which adheres to them in the firft cry- 

 flallization. 



"Nitric aqid con- 

 t^inated in its 

 /irft portions 

 with iruriatic. 

 Why, according 

 to B&rthollet. 



True reafon is 

 the piefence of 

 an excefs of 

 water. 



Conc^nt'-ating 

 the acid in- 

 fuftclent, if 

 the proportion 

 of litharge be 

 improper, and 

 the diftiilation 

 c-^rried 10 dry* 



K&fs. 



xxr. 



Obfenations on the Re^ification of Nitric Acid, bj/ Mr. Stein- 

 ache r , Druggiji at Paris.* 



It has long been known, that the firft portions of nitric acid 

 diftilled from litharge contain muriatic acid. Berthollet ex- 

 plains this phenomenon by faying, that the oxide of lead di- 

 viding its aflion between the two acids, both are fubje6led to 

 the a6tion of expanfibility produced by the heat. Meflfrs. 

 Welter and Bonjour atfert, that, if muriate of filver be em- 

 ployed^ oxigenaled muriatic acid is formed, which rifes with 

 the firfl portions. If I may be allowed to give the refults of 

 my labours after thofe of fo many able chemifts, I would fay, 

 that, when the nitric acid has been fufficiently concentrated 

 before being fubje£led to redification on filver, or on oxide of 

 lead, the firfl part of the rectified acid is found on trial to 

 contain no muriatic acid, notwilhftanding the nitric acid con- 

 tained much of it after its concentration; aiod hence I infer, 

 that an excefs of water is the true caufc, that diminifties the 

 attraftion of the muriatic acid for the oxide of lead or of 

 filver. 



The operator however would in vain expe6l to fucceed by 

 merely concentrating his acid before reftifying it, if he ufed a 

 determinate proportion of litharge, or dillilled to drynefs, as 



Van Mons's Journal d£ Qbimie, Vol. VI. p. 88. 



feveral 



