CHEMISTRY. 



81 



than ncetyl chloride, while it is also much more 

 Mal'lc and has an odor somewhat resembling 

 that of carhonyl chloride. Water dissolves about 

 20 times its volume of the gas, but the liquid 

 does nut mix with water. Alcohol, ether, ben- 

 zinc, and chloroform dissolve it in all propor- 

 tions. 



A complex nitrosilicate salt of silver, con- 

 taining silica, nitric acid, and silver oxide, is de- 

 M-riU'd by G. Rousseau and O. Tito. It is ob- 

 tained liy heating for sixty hours silver nitrate 

 with water in the presence of fragments of mar- 

 ble and appears in ruby-red crystals. 



An interesting account has been published by 

 Dr. Mer/. of Zurich, of a compound of nitrogen 

 and magnesium known as magnesium nitride, 

 MgaN'i. Magnesium, like boron, appears to pos- 

 sess a considerable affinity for nitrogen. The 

 nitride had been obtained by Deville and Caron 

 during their distillations of magnesium for ob- 

 taining the pure metal, and by Briegleb and 

 Genther by heating magnesium filings in the 

 presence of a stream of nitrogen. Dr. Merz de- 

 scribes two simple methods of obtaining it. Mag- 

 nesium nitride is described by him as a light, 

 voluminous, friable, and yellowish -gray sub- 

 stance when cold, but reddish-brown while hot. 

 When exposed to the air it smells strongly of 

 ammonia, owing to its decomposition by the 

 moisture present. Heat is developed, with hiss- 

 ing, increase of volume, and escape of steam, 

 just as when quicklime is slaked when water is 

 poured upon it. Ammonia is also evolved in 

 large quantities and white magnesium hydrate 

 remains. 



The probable existence of a new element is re- 

 ported bv II. D. Richmond and Hussein Off, of 

 the khedivial laboratory, in Cairo. It is found 

 in a new Egyptian mineral called masrite, which 

 was discovered in 1890 by Johnson Pasha in one 

 of the dried-up river beds of Upper Egypt. Sus- 

 picion that the mineral contained some hitherto 

 unknown constituent was first aroused by the 

 fact that when it was dissolved in water and ex- 

 posed to sulphurated hydrogen and acetic acid, 

 instead of the black sulphide of cobalt, which 

 from its supposed composition should have been 

 first precipitated, a white insoluble substance 

 was thrown down, and not till this was ex- 

 hausted did the black cobalt precipitate nppear. 

 The chloride, hydrate, and oxalate of the new 

 element were obtained, and from the analysis of 

 them it appeared to be a divalent element hav- 

 ing an atomic weight of 228. An element of 

 atomic weight about 225 is required to occupy a 

 vacant place in the periodic system in the beryl- 

 lium-calcium group, and this may be the sub- 

 stance. Metallic masrium has not yet been ob- 

 tained. The name given to the new element 

 and its mineral is derived from the Arabic name 

 of Kgypt, Masr. 



New Processes. An apparatus is described 

 by T. B. Thorpe by which the phenomena of a 

 coal-dust explosion, resulting either from a local 

 explosion of fire damp or by the direct action of 

 a blown-out shot, may be illustrated. For class- 

 room demonstration he recommends the subMi- 

 tution of lycopodium powder for the coal dust, 

 on account of the greater ease and certainty of 

 the experiment, and also because its use allows 

 the observance of certain phenomena, such as 

 VOL. xxxn. 6 A 



the mode in which the dust that escajro is 

 thrown on projecting objects, and the fact that 

 the explosion gathers strength as it progresses, 

 which is made evident by the gradually increas- 

 ing area of clear space before such objects as the 

 du>t is swept away by the force of the explosive 

 flame. By observations made by means of a 

 Li>t manometer with this apparatus, the author 

 finds that there is no evidence of a diminution 

 of pressure along the sides of the -pa<-<- through 

 which the flame rushes; and he is of the opinion 

 that there is no experimental proof of the valid- 

 ity of the "suction theory" held by certain col- 

 liery managers, which assumes that in conse- 

 quence of this alleged diminution of pressure 

 occluded fire damp is drawn out from the coal, 

 and contributes to the violence of the explosion. 



The Parkinson oxygen process is a modifica- 

 tion of the method patented by Tessie du Motay 

 many years ago for preparing oxygen by blow- 

 ing steam over potassium manganate, in which 

 the permanganic acid loses part of its oxygen 

 and is converted into a lower oxide of manganese 

 with formation of caustic potash. On reheating 

 this mixture in contact with air the lower oxides 

 of manganese absorb oxygen from the air and 

 become converted into potassium manganate, 

 and thus by alternate heating in presence of air 

 and blowing steam over the mixture a constant 

 supply of oxygen is produced. The process, 

 after having been employed for some time with 

 bases, was disused, mainly because of the little 

 use that was found at the time for pure oxygen. 

 Parkinson's process differs from Du Motay's in 

 that Parkinson brings air in contact with his 

 heated manganates under pressure, and removes 

 the oxygen which has been' absorbed by the 

 manganates under a vacuum. He does not, 

 however, by his present appliances remove all 

 the oxygen from the air, and can not therefore 

 prepare directly by his process pure nitrogen. 

 The novelties in his process lie in the mechanical 

 appliances for heating the manganates; in the 

 use of pumps, etc., for supplying air to the re- 

 torts and withdrawing oxygen from them ; and 

 in his method for bringing the manganates into 

 a porous condition, so that the air may act upon 

 them more easily, which is done by mixing into 

 a plastic mass or paste the ground permanganates 

 with china clay or similar inert material. 



Cyanide of potassium was formed by Bunsen 

 and Playfair by heating charcoal and potassium 

 carbonate to redness in an atmosphere of nitro- 

 gen. Since then Marguerite and Sourdeval have 

 shown that barium carbonate may be used in 

 place of the potash, and that the barium cya- 

 nide produced may be again decomposed by steam 

 into ammonia and barium carbonate. These re- 

 actions afforded a theoretically continuous pro- 

 cess for the conversion of atmospheric nitrogen 

 into ammonia, which, if it could be worked on a 

 large scale, might be of great value. A series of 

 experiments by Prof. Hempel were intended to 

 show a way of obtaining a more abundant yield 

 of the cyanide from the mutual action of the 

 charcoal, nitrogen, and base by the use of greatly 

 increased pressure. A largely increased, amount 

 of barium cyanide was formed. 



A. Villon s method for obtaining colorless tan- 

 nins from tanning drugs includes the three chief: 

 operations of lixiviation of the tanning matters. 



