Chemical Science, 481 



From these experiments it appears, l.That prussic acid cannot 

 be discovered in animals poisoned by small quantities of it after 

 exposition of these bodies for two or three days to the air. 2. 

 That the disappearance of the poison in the viscera after a longer 

 period than this is due to its decomposition, which is favoured by 

 the contact of the putrescent animal matter. 3. That when it is 

 necessary to examine a body judicially to ascertain the presence of 

 this poison, it is important that it should be done as quickly as 

 possible. — Jour, de Chimic Med, Dec. 



12. On the presence of Ammonia in the natural oxide of Iron, 

 by M. Chevallier. — Austin stated that ammonia was always formed 

 when iron rusted in contact with water and the air. M. Chevallier 

 having taken every precaution to exclude ammonia, heated two 

 ounces of clean iron-turnings in a crucible, and when cold put 

 them with one ounce of water into a flask, having its mouth 

 plunged under mercury. At the end of ten hours reddened litmus 

 paper which had been introduced into the flask was restored to 

 blue, and four days after the water saturated by muriatic acid gave 

 a sensible quantity of sal ammoniac. The same result was obtained 

 upon every repetition of the experiment, thus proving what Austin 

 had advanced. 



Having collected various specimens of native oxides of iron, M. 

 Chevallier then heated them in tubes, and obtained ammonia from 

 them all ; but being led to the objection that might be urged of its 

 having been produced from animal matter, he proceeded to operate 

 by washing the finely-pulverized ores with boiling water : in this 

 way he always procured traces of ammonia ; one hundred and fifty 

 grammes of the red hematite of Spain gave two grammes of mu- 

 riate of ammonia, which is one seventy-fifth of the whole weight 

 of the substance. — Annates de Chimie, xxxiv. 109. 



13. Volcanic Muriate of Ammonia of the Isle of Lanzerole, 

 Dr. Brandes. — On July 29, 1825, an earthquake occurred in the 

 island ; on the 30th much subterranean noise, and on the 31st, at 

 seven o'clock A.M., the earth opened about a league to the west of 

 the capital between Tao and Tia-Agua, and half a league from 

 Mont Francia. Flames came from the aperture, and stones in 

 such quantity, that a high hill was formed in twenty-four hours. 

 The eruption was strongest on the night of the 31st, the whole 

 island being enlightened. On Aug. 1, at ten o'clock A.M., the 

 fire ceased, but much smoke issued, which, by the 2nd, had formed 

 three columns, one black, one white, and a third red, which was at 

 some distance from the others. Many cisterns became dry. On 

 the 4th of August there was still much smoke ; on the 22nd, at 

 seven o'clock A.M., the volcano threw out water, which continued 

 to flow for several days. The lava ejected covered a space of half 

 a league in length, and a quarter of a league in width, and was 



