S!)6 Scientific Intelligence. [Nov. 



3. The aqueous solution is not precipitated by sulphate of 

 iron, sulphate of copper, sulphate of zinc, or nitrate of silver. 



4. Nitrate of mercury, and superacetate of lead, occasion 

 brown flocky precipitates ; but both of these salts were precipi- 

 tated white Ijy distilled water. 



5. The acids occasion no precipitation in the aqueous solution. 



6. The alcohol solution was precipitated dark brown by sul- 

 phate of iron and sulphate of copper. 



7. When a weak solution of carbonate of potash is poured 

 upon this ulmin, a dark brown solution is immediately effected, 

 which possesses all the properties formerly described in my paper 

 on ulmin, in the first Number of the Annals of Philosophy. 



1 burned five grains of this ulmin in a platinum crucible. A 

 white ash remained, weighing 0*27 grain. It contained no per- 

 ceptible portion of alkali, but dissolved with effervescence in 

 nitric acid, and was wholly carbonate of lime. 



The most striking property of ulmin is its affinity for car- 

 bonate of potash. It is by means of carbonate of potash that it 

 is usually so soluble in water. The acids throw if. down, merely 

 by depriving it of its potash. The metalline salts throw it down 

 from its alkaline solution by a double decomposition. 



II. Ulmin from the Horse-Chesriut. 

 Mr. Sowerby was so obliging as to send me a specimen of a 

 black matter which lie collected from a horse-ehesnut [ALsoulns 

 hippocampus) growing in a garden in Southgate. In appearance 

 and taste it resembled former specimens of ulmin veiy closely; 

 but it was so much mixed with portions of the bark of the tree, 

 that I could hardly obtain any quantity in a state of perfect 

 purity. Ten grains of it (not free from bark) being burnt in a 

 platinum crucible, left 1*44 grain of a white ash. This consisted 

 chiefly of carbonate of potash mixed with a little carbonate of 

 lime, and with a portion of silica, which I could not weigh, but 

 estimated at about 001 grain. It was dissolved in nitric acid, 

 and shot into small crystals of saltpetre. It appears, then, that 

 this ulmin contains Jess potash than the ulmin from the elm. 



Five grains of it being treated with water, formed a dark 

 brown solution, and left behind a portion of black looking 

 matter, which I found to be bark. This solution was not preci- 

 pitated by acids, nor by sulphate of zinc, nor muriate of tin. 

 Sulphate of iron threw down a grey precipitate ; sulphate of 

 copper, a green ; nitrate of silver, a white ; and acetate of lead, 

 a yellow. 



• These differences from the ulmin of the elm seem to depend 

 upon the smaller quantity of potash present, which prevents water 

 from dissolving so great a quantity as to be precipitated by acids. 



III. Fall of Stones from the Atmosphere, near Chester. 

 I received some weeks ago a letter from Chester^ dated. the 



