Chemical Science. 411 



21. Chemistry applied to industrious Economy. — A new method 

 of killing animals, without causing them pain, has been 

 adopted in London : they are made to expire by means ol 

 nitrogen gas. By this means the meat is rendered much more 

 fresh, of a more agreeable taste, and may be preserved for a 

 greater length of time. A great number of the butchers of 

 London already employ this process. — Revue Encyclopedigtie, 

 torn, v., p. 185. 



22. Red Fire. — The beautiful red fire which is now so fre- 

 quently used at the theatres, is composed of the following 

 ingredients: — 40 parts dry nitrate of strontian, 13 parts of 

 finely powdered sulphur, 5 parts of chlorate of potash (oxymu- 

 riate of potash), and 4 parts of sulphuret of antimony. The 

 chlorate of potash and sulphuret of antimony should be pow- 

 dered separately in a mortar, and then mixed together on paper ; 

 after which they may be added to the other ingredients pre- 

 viously powdered and mixed. No other kind of mixture than 

 rubbing together on paper is required. Sometimes a little 

 realgar is added to the sulpluiret of antimony, and frequently 

 when the fire burns dim and badly, a very small quantity of 

 very finely powdered charcoal, or lamp-black, will make it 

 perfect. 



III. Natural History. 



^. 1. Mineralogy, Geology, Sfc. 



1. Carbonate of Iron, — M. Berthier has found carbonate o 

 iron in the department of I'Yonne, near the village of Burain 

 dispersed through a bank of ochre, and the sandy clays 

 that accompany it. The ochre rests upon a compact argil- 

 laceous limestone. The carbonate of iron occurs in irregular 

 rounded masses ; sometimes of a large size, and distributed 

 here and there without any order. These pieces are of a brown 

 colour, without lustre, heavy, not hard. They disintegrate on 

 exposure to the air, and crumble between the fingers. At first 

 sight they appear like a mixture of bituminous clay and pyrites 

 in very minute grains ; but when attentively examined, prove 



