^S A Dye from the Leaves of the Aloe. 



This juice then produces a fuperb tranfparent colour with- 

 out body, highly proper for works in miniature, and which 

 when diilblved in water may ferve alfo, either cold or warm, 

 for dyeing filk from the lighted to the darkeit fhade. 



Silk, even without a mordant, ftrikes and becomes impreg- 

 nated with this dye. It is equally attra£ted by fulphurated 

 filk, though the latter is fo little difpofed to aflume any colour 

 whatever. 



The aloe, indeed, is not a plant indigenous in our climates ; 

 but this is an inconvenience which it has in common with 

 almoft all fubftances ufed for dyeing, and even with a great 

 number of thofe which ferve us as food. 1 he juice might 

 be procured from Socotora itfelf, not fuch as it is found in 

 commerce infpifTated by fire, but dried in the air, or prepared 

 by an acid. 



Befides, as this plant grows without any difficulty in our 

 "botanical gardens, we may hope to multiply it enough by 

 cultivation, particularly in the fouthern parts of Italy, in 

 order to extract from it the juice ourftlves. 



The value of this new colour may be readily difcovered, 

 when we obferve that, by its property of not being altered 

 by acids or alkalis, it poffefTes the uncommon quality of not 

 being fufceptible of becoming fpotted. 



When we confider alfo that the oxygen, which difcolours 

 our cloths and filks fo as to render them white, is, as one 

 may fay, the principle which develops the colour of the aloe ; 

 it ought to be inferred, that the air cannot aher a quality 

 which it communicates itfelf ; and we may therefore con- 

 clude, that we have difcovered in the aloe one of the moft 

 durable colours known in nature. 



XIII. i 



