178 Miscellaneous TntelUgence. 



dull yellow colour, resolved by heat into its two principles. 

 When fused with sulphur they unite together ; its com- 

 pound with phosphorus is of a fine red colour, and when dis- 

 solved in water, occasions the formation of phosphuretted hy- 

 drogen, and' a phosphate. 



This substftnce has extraordinary powers of resisting heat. 

 It might be taken for an earth, or metallic oxide, in this re- 

 spect. The following are given as experimental demonstrations 

 of its properties. An acid solution, put on a plate of zinc, 

 gave a yellow spot with metallic splendour. This, well 

 washed, dissolved in an acid, and tested by triple prussiate of 

 potassa, gave a blue-white precipitate ; the blue colour being at- 

 tributed to the new substance. The solution that had acted on 

 the zinc gave no blue colour with the test, but only a white. 



A portion of it mixed with lamp-black and oil, and heated 

 violently in a crucible for half an hour, left a reddish crust, the 

 solution of which, in acids, gave an azure precipitate with the 

 triple prussiate. 



The azure matter burnt in the fire with facility, and left a re- 

 siduum of a bright red colour, if the heat had been intense ; but 

 if moderate and continued, the residuum is scarcely red, and 

 ■when placed in water produces flocculi of the substance and 

 bubbles of the gas. 



Ammonia dissolves the substance, making it first yellow, then 

 green ; when heated moderately, a residuum is obtained of a 

 yellow metallic colour; if more heated it becomes white, and 

 does not seem to differ from the substance first dissolved. The 

 yellow matter dissolved in dilute acid gives a red tint to ferro- 

 prussiate of potassa, which exposed to the air becomes green. 

 Other changes take place. 



Nitric acid appears to alter the nature of the new substance. 

 When it is added in a concentrated state to the substance or its 

 salts, the prussiate does not then produce a blue precipitate, but 

 a yellow tinge. Sulphuric acid, when assisted by heat offers 

 similar phenomena. 



One cannot help suspecting, that the blue precipitates in 

 these experiments are occasioned by iron, and yet it is difficult 

 to conceive how that metal, if present, should escape the ob- 

 servation of Dr. Brugnatelli. Further experiments are required, 

 and of a more decisive nature, to clear up this matter. 



8. Effects of Copper on Vegetation. — Some time since (says 

 Mr. Phillips) I accidentally spilt some solution and oxide of 

 copper near the rooi of a young poplar tree, in a short time the 

 tree began to droop ; the leaves on the lower branches dying 

 first, and eventually those on the upper ones. On cutting a 

 branch from the tree, I observed that the knife was covered 

 with copper to the whole breadth of the branch, shewing that 



