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lutions of 1*102, which gave, by evaporation, more than 

 i-6th of their weight of soHd matter. 



Five hundred grains of the strongest infusion of catechu 

 from Bombay, furnished only 41 grains of soHd matter; 

 which, from analysis, appeared to consist of 34 grains of 

 tannin, or matter prc:cipitabie by gelatine, and ^ erains that 

 were chiefly a peculiar extractive matter, the properties of 

 which will be hereafter described. 'Die quantity of solid 

 matter given by the strongest infusion of the Bengal cate- 

 chu was the same, and there \\'as no sensible difference ia 

 its composition. Portions of these solid matters, when in- 

 cinerated, left a residuum which seemed to be calcareous ; 

 but it was too small in quantity to be occurately examined, 

 and it could not have amounted to more than -y^th of their 

 original weights. 



The strongest infusions of catechu acted upon the acids 

 and pure alkalis in a manner analogous to the infusion of 

 galls. With the concentrated sulphuric and muriatic acids, 

 they gave dense light fawn-coloured precipitates. With 

 strong nitrous acid they effervesced ; and lost their power 

 of precipitating the solutions of isinglass, and the salts of 

 iron. The pure alkalis entered into union with their tan- 

 nin, so as to prevent it from being acted upon by gelatine. 



When the solutions of lime, of strontia, or of barytes, 

 were poured into the infusions, copious precipitates, of a 

 shade of light Ijrov. n, were formed ; and the residual fluid 

 assumed a paler tint of red, and was found to have lost its 

 power of precipitating gelatine. 



After lime had been boiled for some time with a portion 

 of the infusion, it assumed a dull red colour. The liquor 

 that passed from it through the filter had only a faint tint 

 of red, did not act upon gelatine, and seemed to contain 

 only a very small portion of vegetable matter. Pure mag-; 

 ncsia, when heated with the infusion, acted upon it in an 

 analogous manner; the magnesia became light red, and the 

 residual fluid had only a very slight tinge of that colour. 

 With carbonate of magnesia, the infusion became deeper 

 in colour, anil lost its power of precipitating gelatine j 

 though it still gave, with oxygenated sulphate of iron, a 

 light olive precipitate. 



The carbonates of potash, of soda, and of ammonia, in 

 tlicir concentrated solutions, produced only a slight degree, 

 of turbidness in the infusion of catechu: they communi- 

 cated to ihcm a darker colour, and deprived them of thq 

 power of acting upon gelatine; thouyh this power was rc- 

 ■lorcd by the addition of an acid. 



O 3 After 



