I'jgl. A >fEvV VARNISH. 177 



filk. of thofe large eleftrical machines which now are 

 found to produce fuch great efFecls. 



There is found in Provence (a fouthern province of 

 France) at the roots of the Chondrilla 'Juneca Lin^ 

 very common in fleril land, a kind of glue produced by 

 an exudation of a kind of milky juice from that 

 plant, which greatly refembles the elaftic gum. The 

 milky juice of the fig-tree, of feveral kinds of I'ltby^ 

 mails and Apocyfiium, produce alfo, we are told, par- 

 ticularly in the meridional parts of France, a iubllance 

 which has a great analogy with the elaftic gum. 



Mr. Faujas de St. Fond gives the following receipt 

 for making a varniih that may be employed for cover- 

 ing baloons, electrical lilken cylinders, or other lilks, 

 impenetrable by v^ater, which will prove nearly as good 

 as that of elaftic gum (difl'olved in oil), and is much 

 lefs expenfive. 



" Take, fays he, a pound of glue * ; put it in a new 

 earthen pot ; make it boil flowly for about an hour^ 

 till it ceafes to bubble, or, what comes to the fame , 

 thing, till, upon trial of a drop of it takes fire, whea 

 thrown upon a live coal. Pour then upon the glue 

 a pound of fpirit of turpentine, ftirring it well with a 

 wooden fpatula, and removing the pot from the flame, 

 left the whole fhould take fire j. — let it boil for five or 

 fix minutes; pour then upon it three pounds of boiling 

 oil, that has been prepared with litharge. Walnut oil, 

 linfeed oil, or poppy oil, may be employed at plea- 

 fure. Stir it well, and allow it to boil for a quarter 

 of an hour; and the varniih is made. 



"When it has flood 14 hours, and the fedlment has 

 fallen to the bottom, poor off the clear into another 

 veflel. W^hen you are to ufe it, let it be warm, and 

 lay it on with a flat pencil, upon filk, well Jlretched. 

 One good coat is enough. Allow it to remain thus 

 11 retched out in the open air to dry." 



• This, though not cxpreffed in the receipt, I prefume means tha 

 glue of Holly, or birdflinic above dcfcribe^. 



Vox,, III. t Z 



