Maech 30, 1900.] 



SCIENGU. 



5.17 



described recently arsenids and antimonids of 

 calcium which on treatment with water yield 

 respectively arsin AsHj and stibin SbHj. 



Another new compound of considerable in- 

 terest, N3I, has been prepared by Professor 

 Hantzsch, of the University of Wiirzburg, and 

 is described in the last Berichte. This is pre- 

 pared by the action of iodin on the silver salt 

 of hydrazoic acid, AgN3. Unlike the other 

 iodids of nitrogen which are dark brown, this 

 is almost colorless. It seems to rather resemble 

 the iodid of cyanogen CNI, which is formed in 

 an analogous way, being soluble in water and 

 of an almost intolerable odor. It is, however, 

 very explosive, being even more unstable than 

 the other iodids of nitrogen. 



In a recent number of Nature, E. A. Hadfield 

 describes a contribution which his firm has 

 made to the contest of armor plate vts. projectile. 

 The latest improvement in the armor plate is 

 that of Krupp, the composition of the steel used 

 aflfbrding exceeding toughness and great tensile 

 strength combined with high elastic limit. The 

 surface is hardened by carburization by gas 

 cementation instead of by charcoal, as in Har- 

 veyized plates. Against these plates ordinary 

 projectiles are broken to pieces, their striking 

 energy being wasted in breaking themselves in- 

 stead of in perforating the plate. Hadfield' s 

 projectiles however, when used with a slightly 

 higher velocity than the average usually em- 

 ployed, perforate these plates readily. These 

 projectiles are fitted with a soft metal cap, 

 which takes up a part of the energy which 

 would otherwise be used in shattering the pro- 

 jectile. 



In this connection it may be added that the 

 daily press has published a statement from T. 

 A. Edison, Jr., that he has now devised a new 

 armor plate which has a resistance much 

 greater than the Krupp plate, so that for equal 

 strength, the thickness of the plate can be re- 

 duced nearly one-half. At the same time the 

 cost of the plate is very materially less than 

 that of the Krupp or even of the Harvey plate. 



The preparation of some nickel bi-onze alloys 

 is given by Sergius Kern of St. Petersburg, in 

 the Chemical News. These alloys are especially 

 prepared for fittings in high pressure marine 



boilers, and contain 70 per cent, copper, 17J to 

 20 per cent, nickel, and the balance zinc. The 

 alloys rust very slightly, have a tensile strength 

 of 26 to 36 tons per square inch, and elongation 

 of 14 to 17 per cent, in 2 inches. 



The discovery of a series of magnesium-alu- 

 minum alloys is reported in Engineering. When 

 containing 10 per cent, magnesium the alloy 

 I'esembles zinc, with 15 per cent, brass, and 

 with 20 per cent, bronze. They give good 

 castings and are resistant to the atmosphere, 

 are fairly hard and work as well as brass. The 

 alloys are lighter than aluminum and while 

 possessing no great strength, are of value for 

 many purposes where a light metal like alum- 

 inum would be used, if it could be cast and 

 worked successfully. The inventor, Dr. Lud- 

 wig Mach has named the alloys magnalium. 



J. L. H. 



SCIENTIFIC IfOTES AND NEWS. 



The French Association for the Advancement 

 of Science meet at Paris from the 2d to the 9th of 

 August, under the presidency of General Sebert. 



The Ways and Means committee of the New 

 York legislature has reported an item of $60,- 

 000 for the purchase of the scientific collections 

 and library of the late Professor James Hall, 

 State geologist and paleontologist for over sixty 

 years. Should this report be sanctioned by the 

 Senate and the Governor, the State Museum will 

 acquire an immense collection in invertebrate 

 paleontology, comprised principally of material 

 from the New York formations. The library is 

 the sum total of all the books brought together by 

 Professor Hall during his remarkably long and 

 active career and will make a unique addition 

 to the State Library. It is hoped that no op- 

 position will be manifested to the completion of 

 this purchase. 



Professor David Edward Hughes, the 

 eminent physicist, has left the greater part of 

 his large estate to four London hospitals, which 

 will receive ultimately between $1,500,000 and 

 $2,000,000. As these hospitals have medical 

 schools attached to them, the money will 

 doubtless be used in large measure for educa- 

 tional and scientific work. Professor Hughes 

 also bequeathed $20,000 each to the Royal So- 



