Royal Society, 69 



Fleitmann communicates a process for estimating copper. 

 The solution of copper, when freed from nitric acid and metals 

 which might hinder the action, is precipitated by means of pure 

 metallic zinc, and the precipitated copper well washed out. It 

 is then dissolved in an acid solution of perchloride of iron : this 

 takes place very rapidly, and gives twice the quantity of proto- 

 chloride of iron, which may be estimated by permanganate of 

 potash in the usual way. 



Wicke investigated the quantity of butter contained in goat's 

 milk taken in the morning, at noon, and in the evening. The 

 quantity of butter at those times is respectively as 4*6 : 4!'9 : 5*2. 

 The average quantity of butter is 4*9 per cent. Cow's milk 

 contains, according to Playfair, the same amount. 



Pebal continues his investigations on the constitution of citric 

 acid. It is not possible with our limited space to give any 

 adequate idea of his paper, as he enters very much into theore- 

 tical considerations. 



VIII. Proceedings of Learned Societies, 



ROYAL SOCIETY. 



[Continued from vol. xi. p. 265.] 



Dec. 6, 1855. — Sir Benjamin Brodie, Bart., V.P., in the Chair. 



HE following communication was read : — 



" Results of the Examination of certain Vegetable Products 

 from India."— Part I. By John Stenhouse, LL.D., F.R.S. 



Through the kindness of my esteemed friend Dr. Royle, I have 

 been permitted to select such vegetable products from the extensive 

 collection at the India House as seemed most likely to repay the 

 trouble of investigation. My attention, during the last twelve 

 months, has been chiefly directed to three of these vegetable sub- 

 stances ; and the results of their examination I now take the liberty 

 of submitting to the Royal Society, to be followed by those of the 

 others as they may be completed. 



Datisca cannahina. 



The first of these substances which I examined consisted of a 

 quantity of the roots of the Datisca cannabina, from Lahore, where 

 this plant is employed to dye silk of a fast yellow colour. The 

 roots, which had been cut into pieces about 6 or 8 inches long, were 

 from a half to three-quarters of an inch in thickness. They had a 

 deep yellow colour. A decoction of the leaves of the Datisca canna- 

 bina was examined by Braconnot in 1816, who discovered in it a 

 crystallizable principle, to which he gave the name of datiscine. 



T 



