24^ On a nev> Kind of Painting 



tlons, diflolved in an indeterminate quantity of water, con- 

 llanlly united to pure foda, which reduces the albuminous 

 fubftance to an almoft faponaceous ftate. There is found 

 alfo in the fcrum phofphate of foda, of lime, and of ammo- 

 nia. But thefe falinc fubltances are not eircntial to this com- 

 bination, fince they not onlv niav vary in their proportions, 

 but be wanting either in whole or in part; and even unite in 

 the fcrum to other falls, fuch as the muriate of potaOi, the 

 phofphate of magnefia, &c., without the albuminous, alka- 

 line, or gelatinous lubdance of the feriim being changed, or 

 exhibiting different charafteriftic properties. 



This dodrine, received bv all the celebrated modern che- 

 mifts, induced me to think that the albuminous fubftance of 

 ferum, modified by its combination with eelatin and foda, 

 ought to form with calcareous earth a compolilion which 

 woidd retain no more of that vifciditv and tenacity afllimed 

 by the mixture of the while of an egg and lime, than what 

 might be necefllary for anfvvcring the propofed end. 



Thefe reafons, and the low price of this liquid in large 

 cities, foon induced me to trv the eft'eils of the ferum of 

 blood with pulverized quicklime ; and I found, with much 

 fatisfa<ftion, that my firfi trials correfponded in every refpe6l 

 to the hopes I had conceived. 



FraBice and Appl'ifailon qJ ll:e new Kind of Painting. 



The preparation of this new kind of paint is eafy, and re- 

 quires very little time. Nothing is neceifary but to pulverize 

 the lime, and to dilute it in the ferum of blood until it forms 

 a liquid of fuf!icicnl thicknefs for painting; which is then to 

 be applied in the ufual manner. The colour which this 

 compofition acquires is whitiih, and more or lefs fliining, ac- 

 cording to the purity of the ferum and the whitcnefs of the 

 lime. This earth may be employed either in the liate of 

 quick or cauftic lime reduced to powder, or well flaked 

 with a fmall quantity of water to lelVen the adiicfion of its 

 integrant parts. It muft then be reduced to a fine powder, 

 and be fifted through a clofe lieve. If kept for fome davs, it 

 is necefl'ary to ijreferve it in a clofe tub or earthen vdf'e), to 

 prevent its comi;;iuation with the carbonic acid and water of 

 the almofphere. The ferum is feparated from the curdled 

 blood by decantation : bu't care muft be taken to fhake the 

 matter as little as pofTible, and to fuffer it each time to re- 

 main at reft. 



In this compofition two things only arc to be obferved : 

 the Srft IS, that ferum being a fluid highly lufccptible of cor- 

 ruption, it muft be employed the fame day it is feparated ; or 

 "■■ ' at 



