644 SCIENTIFIC RECORD FOR 1883. 



Dr. Bolton gives the following : 



Table showing approximate relative disintegration of rocJc forming [and . 

 associated) minerals by citric acid in solution. 



(Proceedings Am. Assoc. Adv. Science, xxxi, 271.) 



New Explosives. — Pyronome is the name given by M. Sandoy to a new 

 explosive mixture consisting of 69 parts saltpeter, 9 of sulphur, 10 of 

 charcoal, 8 of metallic antimony, 5 of potassium chlorate, 4 of rye flour, 

 and a few centigrams of potassium chromate. These are to be mixed 

 in an equal volume of boiling water, and the mass evaporated down to 

 a paste, dried and powdered as wanted. This mixture is said to be 

 cheaper than dynamite, but its manufacture and use must be attended 

 w r ith considerable danger. 



S. H. Hinde proposes a new explosive mixture composed of 64 parts 

 of nitroglycerine, 12 of ammonium citrate, 0.25 of ethyl palniitate, 0.25 

 of calcium carbonate, 23 of coal, and 0.50 of sodium carbonate. The 

 special advantages of this complex mixture do not appear. 



A new explosive has just been pateuted in England by Dr. C. W. 

 Siemens. The compound is a mixture of saltpeter, chlorate of potash, 

 and a solid hydrocarbon, and is suitable both for mining purposes and 

 fire arms, while, if ignited in the open air, the combustion takes place 

 slowly and imperfectly, and, therefore, without danger. The new com- 

 pound, which has about the same density as ordinary gunpowder, and 

 is very hard, possesses with equal volume more than double the ex- 

 plosive force of the latter. The intensity of explosion can be regulated 

 at will by varying the proportions of the ingredients and the size of the 

 granules. (Munroe's Notes on the Literature of Explosives.) 



Use of Limed Goal in Gas-making. — Prof. J. Alfred Wanklyn read a 

 paper on the above subject before the British Association for the Ad- 

 vancement of Science at the Southport meeting in August, 1883. 



As the gas manufacture is usually carried on, only a small part of 

 the nitrogen contained in the coal is recovered in the form of ammonia; 



