EXCELLENT COPAL VARNISH. (ft 



phosphates, borates, or muriates, which might have been 

 suspected from the situation where it was found. 



The glauberite was brought from Spain by Mr. Du- Where found, 

 meril. It has hitherto been found only at Villarubia, near 

 Ocanna, in new Castile. Its crystals are sometimes solu 

 tary, sometimes in clusters, and disseminated in masses of 

 sal gem. Mr. Brongniart has not been able to find any 

 mention of this mineral, either in the works of minera- 

 logists, or in those of travellers in Spain, that he could 

 consult. 



XV. 



An excellent colourless Copal Varnish. By Mr. Lenor- 

 mand, late Professor of Natural Philosophy*. 



Ei 



«VERY one knows the difficulty of dissolving copal com- Copal difficult 

 pletely, when we attempt to make a varnish, I hasten there* of soluuon « 

 fore to communicate a method, that has succeeded perfectly 

 with me ; and which will be found, to produce a very fine 

 varnish with this substance. 



All copal is not fit for making this varnish, it must there- Method of se« 

 fore be selected with care, and the following method will lectin § il > 

 show what is good. Take each piece of copal separately, 

 and let fall on it a single drop of very pure essential oil of 

 rosemary, not altered by keeping. Those pieces on which 

 the oil makes a certain impression, that is to say, which 

 soften at the part that imbibes the oil, are good, and should 

 be reserved for making Varnish. The others are to be re- 

 jected. 



Powder the pieces of copal thus selected, sift the powder and of making 

 through a very fine hair sieve, and put it into a glass, on the tbe Va: °' sb '. 

 bottom of which it must not lie more than a finger's breadth 

 thick. On it pour essence of rosemary to a similar height, 

 stir the whole together with a stick for a few minutes, the 

 copal will dissolve into a viscous substance, and the whole 

 will form a very thick fluid. Let it stand for a couple of 

 hours, after which pour on gently two or three drops of 



* Sonnim's fciVUotbicnie Physica-6conoini<iue for 1808, Vol. IT, 

 ft 193. 



F 2 tery 



