1 . rr - 



SCIENTIFIC NEWS* 



be -thus fpread, and mod probably would not enter the fkm 

 with thedetired effect; or render it as iupp-le as that oil which 

 from experience : they are led lo prefer. 



The celebrated Seguin has directed his attention to this in- 

 gredient of fuch extend ve manufacloring utility. He remarks, »V»nA 

 that this material (by the name of Degras) is of two kinds in 

 France; viz. the common fort and that of Niort. The RtfcQi* .casfei'lct 

 the- immediate prod u 61 of the chamoying of (kins, which are 

 cleared oi' their furplus oil by folution of potalli. It therefore 

 contains not only foap, but likewife gelatine. It is evaporated' 

 to dtynefs and then Md&Degras. At Niort it is decompofed 

 by l'ulphuric acid, and the precipitate is called the Degras of 

 that town. AVl * 



Mr. Seguin finds by analyfis, that this laft is oxigenaled oif, 

 whereas the other is a compound of foap and gelatine. He 

 fucceeded in giving to whale oil all the 'properties of the 

 Degras of Niort, by boiling one pound for a few minutes with 

 half an ounce of nitric acid at 2.5 degrees. He obferved that 

 no gas is difengaged in this operation; but that water and ni- 

 trate of ammonia are formed ; and he concludes that the oil was 

 oxigenaled, nol by abiorbing the oxigen of the acid, but by 

 yielding to it partof the hidrogen which was one of its own com- 

 ponent parts. The refult is the more intcrefting, astheZtegrasof 

 Niort being much more eftcemed th art the common fort,' the -t'uV' Ja^<;M 

 curriers may hereafter, inficad of paying a great price for it, *-** r 



make it in as large quantities as they pleafe by following the 



procefs here indicated. 



.noil ahaooA 



■ 

 Jfqte re/peeling the Decompofdion of Sulphate of Lead % thz 

 Muriatic Acid. By M. Descotixs *. :K ,\ 



If the fulphate of lead be treated with muriatic acid rather Sulphate of lead 



concentrated, that metallic fait is totally diffolved) provided''! 8 fo,ub ! e ! > y h f a t 



the proportionof acid be rather in excels. This' folution re- Muriate of lead* 



quires heat to effect it. Upon cooling, the muriate of lead' fe P arate s by 



cryftallizes in great quantity; and it is much more fpeedTly \^l\ u Jj e ^ 



obtained by the addition of a fmall quantity of cold water, water, and may 



If tb« Supernatant fluid be fenarated from the crvftallizea faf^Yf [ n *■»"» ' 

 * I **■># t»r ' ..^ofedbyfulph, 



* Soc. Fhilom,No. 9G, 

 sail A 



'10 ID .< r Wirt-J 30*i 



