AND OBSERVATIONS ON LAC. ]QT 



When formed into fealing wax, it is employed as a japan, fabling wax, 

 and is Iikewife rnanufa&ured into different coloured var- varni ' hes J 

 nifbes. 



The colouring part is formed into lakes for painters ; a fort lakes, dying j 

 of Spanifh wool for the ladies is alfo prepared with it : and, 

 as a dying material, it is in very general ule. 



The refinous part is even employed to form grindftones, by grind ftones, and 

 melting it, and mixing with it about three parts of fand. For P o]ifliers > 

 making poliflung grind ftones, the fand is filled through fine 

 muflin; but tliofe which are employed by the lapidaries, are 

 formed with powder of corundum, called by them Corune. * 



But, in addition to all the above ufes to which it is applied the Hindu ink} 

 in India, as well as to thofe which caufe it to be in requeil in 

 Europe, Mr. Wilkin's Hindu ink occupies a confpicuous place, 

 not merely on account of its ufe as an. ink, but hecaufe it teaches 

 us to prepare an aqueous folution of lac, winch probably will 

 foe found of very extenfive utility. 



This folution of. lac in water may be advantageous y em- water varni/h 3 

 ployed as a fort of vamifh, which is equal in durability, and 

 other qualities, to thofe prepared with alcohol ; whilft, by the 

 laving of this liquid, it is infinitely cheaper. 



I do not mean however to affert that it will anfwer equally 

 well in all cafes, but only that it may be employed in many. 

 It will be found Iikewife of great ule as a vehicle for colours ; 

 for, when dry, it is not eafily affected by damp, or even by 

 water. 



With a folution of this kind, I have mixed various colours, Th? Htter verv 

 fuch as vermillion, fine lake, indigo, Pruffian blue, fap green, ukfa] - 

 and gamboge ; and it is remarkable, that although the two laft 

 are of a gummy nature, and the others had been previously 

 mixed with gum, (being cakes of the patent water-colours,) 

 yet, when dried upon paper, they could not be removed with 

 a moiftened fponge, until the furface of the paper itfelf was 

 rubbed off. 



In many arts and manufactures, therefore, the folution- of 

 lac may be found oi' much utility ; for, like mucilage, they 

 may be diluted with water, and yet, when dry, are little if at 

 all affeaed by it.f 



We 



* Phil. Tranf. 1781, p. 3S0. 



f The alkaline folutions of lac are evidently of a faponaceotis 

 nature, and, like other foaps, may be decompofed by acids. The 



entire 



