1824.] Scientific Notices — Chemistry. 153 



of phosphate of lime, it is to be concluded that the phosphoric 

 acid is combined with ammonia, and not with lime, and in fact 

 the presence of this compound was determined. 

 Ten parts of the calculus, therefore, consist of 



Substances soluble in Water. 



Lithic acid 1 part 



Lithate of ammonia 4 



Phosphate of ammonia ± 



Substances insoluble in Water. 



Oxalate of lime l± 



Animal matter 2 



Loss and moisture 1 



10 



10. Odour of Hydrogen Gas extraneous, Inodorous Hydrogen Gas. 



When hydrogen gas, obtained from a mixture of iron filings 

 and diluted sulphuric acid, is passed through pure alcohol, the 

 hydrogen loses its odour in a great measure ; and if water be 

 added to the alcohol it becomes milky ; if enclosed in a flask 

 and left for some days, an odorous volatile oil is deposited, 

 which was contained in the gas, and which contributed to its 

 well-known odour. 



Perfectly inodorous hydrogen gas may be obtained by putting 

 an amalgam of potassium and mercury into pure distilled water, 

 but if an acid or muriate of ammonia be added to the water, 

 which accelerates the developement of the gas, it gives it the 

 same odour as that remarked in the solution of zinc by weak sul- 

 phuric acid. This odour, therefore, does not belong to the hy- 

 drogen gas, but is given to it by impurities. Berzelius. — 

 (Journal of Science.) 



1 1. Iodine and Phosphorus. 



" Thenard asserts, that in the union of iodine and phosphorus, 

 not only caloric, but light, is extricated. But Sir H. Davy 

 states that no light is evolved in this process. Repeated expe- 

 riments have convinced me of the accuracy of the observation 

 of the British chemist; but it is only justice to M. Thenard to 

 state, that in the action between these substances, the evolution 

 of light, as well as of caloric, may be shown, according to the 

 mode of making the experiment. If a small piece of dry phos- 

 phorus be dropped into a test-tube, and a quantity of iodine, in 

 its usual scaly form, sufficient to cover the phosphorus, be 

 quickly added, an immediate action ensues; the tube becomes 

 hot; fumes of iodine are disengaged, and a deep violet-brown 

 lmuid is formed, without, the evolution of light, even when the 

 experiment is made in a darkened room. But if the proportion 



