ON TANIN AND ITS SPECIES. 201 



Caelum, or Terrajaponica. 



Cachou is an aftringent : it is foluble in alcohol and Qualities of the 

 in water. It precipitates glue abundantly and forms with itof^anin/ 

 a vinous (q.) magma which has neither the confidence nor Cachou or Terra 

 the infolubility of the tannate of galls. japonica. 



It reduces muriate of gold, it precipitates the muriate of 

 tin and affords a violet coloured ink with red fulphate of iron. 

 It is a tamnfui generis. It dyes filk. 



Dragons Blood. 



That which is pure and comes to us in calebafhes is foluble Dragon's Blood, 

 both in water and in alcohol ; its tafte is harth ; it dyes filk of 

 a bad wine colour. It abundantly precipitates glue, the 

 muriate of tin, the red fulphate, and difoxides gold ; it is alfo 

 a fpecies of tanin. 



Sumach. 



The tanin which this fubftance contains, abundantly pre- Sumach* 

 cipitates glue, and affords a white magma without confidence. 

 Like tanin it is feparated from the decoction of fumach by the 

 carbonate of potafh ; its curdled depofition is again foluble 

 in hot water with the exception of a fmall quantity of chalk. 



Barites and the oxalic acid demonftrate the exiflence of 

 abundance of lime and fulphuric acid ; but it will be neceflary 

 to afcertain by experiments On the green fumach whether 

 fulphate of lime be one of its principles, or an adulteration. 

 The author is not furprifed at finding it, lince he obtained this 

 fait in confiderable quantity from the juice of cabbage, and of 

 folanum lycoperficon, which is cultivated in the gardens 

 under the name of Iomates. This juice alfo contains gallic 

 acid ; it becomes green in the air when faturated with potafh. 

 It reduces gold, decompofes muriate of tin and the red ful- 

 phate, with which it affords a thick ink. 



Yellow Wood, or Fuflic. 



It contains a fpecies of tanin. Like tanin it precipitates Yellow wood or 

 the folution of glue ; a folution of fait is fufficient to precipi* tu * rtlc * 

 tate it. It is foluble in water and in alcohol. It reduces 

 gold, decompofes muriate of tin and the red fulphate, by 

 means of which it dyes filk of a greyifh yellow. 



Fujict 



