Intelligence and Miscellaneous Articles. 157 



sent me the following account of a chemical investigation of the 

 plant, performed in his laboratory and under his eye, by M. F. Bel- 

 lingrodt, which I give in the latter gentleman's own words : — 



"The plants, some of which were still in flower, were collected 

 in the month of October on the Altenberg and in the immediate 

 neighbourhood of its large zinc works. To get rid of adhering 

 earth completely, the fresh, uncut herbage with the roots was 

 washed with water, until, when macerated for sixteen or eighteen 

 hours with water containing muriatic acid, it gave no inorganic 

 matter to the dilute acid. The whole was then finely chopped and 

 digested on the vapour-bath for twelve hours with water and mu- 

 riatic acid ; the vegetable matter was separated from the extract, 

 and this treated with chlorate of potash. The addition of an excess 

 of ammonia to the decolorized extract, now produced a precipitation 

 of alumina, organic substances, and partially of the iron. 



" The precipitate produced in the filtrate by sulphuret of ammo- 

 nium was dissolved in muriatic acid, oxidized by nitric acid, and 

 the iron then completely separated by ammonia. A portion of the 

 filtered fluid was boiled with solution of potash, when traces of man- 

 ganese were precipitated. Solution of sulphuretted hydrogen then 

 rendered the presence of zinc in the filtrate quite evident. 



" Another portion of the fluid filtered from the iron precipitate 

 was precipitated at once by sulphuret of ammonium, the dried pre- 

 cipitate calcined in a platinum crucible, moistened with nitric acid, 

 again calcined, and then treated with dilute acetic acid ; the zinc 

 was precipitated from the solution in acetic acid by solution of 

 sulphuretted hydrogen. 



" From another portion of the herb, freed from external impurities, 

 the juice was expressed, and the presence of zinc in this was also 

 distinctly proved by the above process." 



This metal must therefore be added to the eighteen elements 

 hitherto known to occur in the vegetable organism. — Poggendorff's 

 Annalen, vol. xcii. p. 175. 



ON THE COMPOSITION OF TANNIC ACID. BY A. STRECKER. 



It appears from my experiments, that tannic acid and the tannins 

 in general are much more complex bodies than is generally supposed. 

 In fact, by the action of mineral acids, of alkalies, or of ferments, 

 they are resolved into glucose and a new acid by fixing the elements 

 of water. This resolution, which I announced two years ago, has 

 served me as a starting-point in the determination of the molecule 

 of tannic acid. 



According to the analyses of Pelouze, Liebig and Berzelius, the 

 molecule of tannic acid is expressed by the formula C'^ H^ O'^, and 

 it is supposed that in its neutral salts 3 equivs. of water of this for- 

 mula are replaced by 3 equivs. of metallic oxide. There is never- 

 theless only one tannate (that of lead) which appears from analysis 

 to contain the carbon and metal in the proportion of 18 : 3 equivs. 



Perceiving from the splitting of tannic acid into glucose (C'^H^'^O'^) 

 and gallic acid (C^^H^O'^) that the above formula could not express 



