98 



CHEMISTRY. 



CHESNEY, FKANCIS E. 



pure water, but soluble in water which has 

 been rendered slightly alkaline. 100 parts of 

 hematosine contain 10.750 of mineral matter, 

 wla-ivm are 6.33 metallic iron, equal to 9.043 

 peroxide of iron, leaving 1.707 other mineral 

 matter. Further research exhibited the pres- 

 ence of lime and phosphoric acid in the ash of 

 hematosine, which (the ash) was found to con- 

 sist, in 100 parts, of 84.121 peroxide of iron, 

 13.512 phosphoric acid, and 2.986 lime. 100 

 parts of hematosine consist of 89.25 organic 

 matter, 9.04 peroxide of iron, 1.45 phosphoric 

 acid, and 0.32 lime. 



The Explosion of Detonating Compounds. 

 In his researches on gun-cotton and nitro- 

 glycerine, Prof. Abel advanced the hypothesis 

 that explosion takes place in detonating com- 

 pounds, on the production in most of a certain 

 kind of mechanical action depending on their 

 properties and constitution. On this theory, 

 the heat developed in explosion of the priming 

 is not capable of producing the noticeable 

 change necessary to instantaneous decompo- 

 sition. MM. Champion and Pellet have made 

 this theory the subject of direct experiments, 

 which are reported in the Comptes Eendus. 

 The following is an abstract of their statement : 



First Experiment. Two glass-tubes were joined 

 by a paper band j giving a total length of 2.40, and 

 13m. internal diameter. In each extremity was 

 placed a little paper boat holding 0.03 grains of iodide 

 of nitrogen. The iodide at one end being exploded 

 bv a heated wire, that at the other immediately ex- 

 ploded also. Gradually increasing the length of the 

 tube, it was found possible to explode the same 

 weight of iodide in this way at 7 metres distance. 

 M. Barbe has experimented similarly with dynamite, 

 but he attributes the explosion to the pressure of air 

 caused by expansion of gas. To examine this alleged 

 influence, a small pendulum, consisting of an elder 

 ball suspended by a silk thread, was placed 50 centi- 

 metres from one extremity of the tube, and the iodide 

 at the farther end was exploded. The slight shock 

 given to the pendulum was like what would be given 

 it by blowing into the tube with the mouth. By di- 

 minishing the quantity of iodide, the ball could even 

 be kept from striking the upper surface on explosion 

 taking place. If the tubes are separated by an inter- 

 val of 5 or 6 millimetres, explosion in the above man- 

 ner does not take place, unless the quantity of the 

 compound is very much increased. The direct ex- 

 plosion need not be produced within the tube. A 

 little nitro-glycerine or fulminate of mercury exploded 

 before the mouth of the tube will produce the same 

 effect. 



Second Experiment. Some iodide of nitrogen in a 

 moist state was attached with gold-beater' s-skin to 

 rings of a double-bass ; when it was sufficiently 

 dry, the strings were sounded with the bow. The 

 iodide on the lower strings did not explode. That 

 on the string giving the highest note exploded, on 

 the slightest application of the bow. "When the lat- 

 ter >trin<r was relaxed till it gave si natural, no effect 

 produced by the vibrations. When the sound 

 i-_r:un raised several notes, explosion took place. 

 There appeared to be an inferior limit in the number 

 of vibrations necessary, and this was estimated about 

 60. By putting the two farther removed strings in 

 unison, the explosion caused in the lower induced ex- 

 plosion in the other. No superior limit could be deter- 

 mined in the number of vibrations causing explosion. 

 Third Experiment. Metallic plates appeared to 

 pive the same results as stringed instruments. Two 

 Chinese tam-tams were tried, one having a diame- 



ter of 56 centimetres, and giving vfiry grave Bounds ; 

 the other 47 centimetres, and giving high metallic 

 sounds. Small quantities of iodide of nitrogen were 

 attached by membranes to the centre, the circum- 

 ference, and the intermediate parts. On sounding, 

 the larger instrument caused no explosion ; the iodide 

 on the other exploded when the vibrations had ac- 

 quired sufficient amplitude. 



Fourth Experiment. Two parabolic mirrors, of 50 

 centimetres diameter, were placed opposite each other 

 at a distance of 2.50 m. In the focus of one of them 

 was placed a piece of paper, haying attached to it (by 

 gold-beater' s-skin) a few centigrammes of iodide of 

 nitrogen. Another portion of iodide (similarly at- 

 tached) was placed between the mirrors. In the 

 focus of the second mirror, a large drop of nitro- 

 glycerine was exploded ; the iodide then exploded in 

 the first mirror, while the other portion of iodide 

 was not affected. In these experiments, they remark, 

 the heat, produced by the explosion of the nitro-gly- 

 cerine, having been concentrated in the other focus, 

 caused the explosion of the iodide. According to M. 

 Berthelot, one kilogramme of nitro-glycerine ex- 

 ploding in a confined space gives 19,700,000 calories ; 

 while gunpowder exploding in open air gives only 

 644,000 calories. The quantity of nitro-glycerine 

 that was necessary to explode the iodide in the above 

 conditions was 0.03 grains, and represented 591 cal- 

 ories (allowing the detonation to correspond to that 

 produced in a confined space). The quantity of pow- 

 der giving the same number of calories is 0.9 grains ; 

 one gramme of powder was then exploded in place of 

 the nitro-glycerine, but the result was nil; and it 

 required 8 to 10 grammes of powder to produce the 

 heat necessary to explosion of the iodide in the other 

 focus. 



Newly-found Substances. Acridine is the 

 name given, to a new derivative from anthra- 

 cine, by its discoverers, MM. Graebe and Caro. 

 They obtain it by the following process : The 

 semi-solid portion of coal-naphtha, boiling be- 

 tween 300 and 360 F., is heated with di- 

 lute sulphuric acid, bichromate of potash is 

 introduced, and a brown precipitate appears, 

 which can be dissolved in boiling water. Upon 

 filtration and cooling, this solution yields orange 

 crystals of the chromate of the base, and the 

 free base is yielded up after warming the crys- 

 tals with ammonia. Acridine melts at 107 

 F., and distils at a point above 360, is 

 insoluble in cold water, and slightly soluble 

 in boiling water, but easily dissolved in alcohol, 

 ether, and the bisulphide of carbon. Its dilute 

 solution give a beautiful olive color by reflected 

 light. It takes its name acridine from its irri- 

 tating action on the skin and mucous mem- 

 brane. The discoverers do not mention any 

 useful purpose to which it may be applied. 



M. Moriri has succeeded in separating a sub- 

 stance, which he calls galactine, from animal 

 organisms sometimes constituent element, 

 sometimes morbid product. It is found in the 

 blood and the gastric juices, also in liquids 

 produced by disease. It closely resembles gela- 

 tine, to which it inay be transformed by the 

 prolonged action of water or heat. Galactine 

 is soluble in water, but not in alcohol, and may 

 be precipitated by a solution of tannin. In 

 nutritive qualities, it is thought to rank witli 

 albumen, fibrine, and caseine. 



CHESKEY, General FRANCIS BAWDON, 

 D. C. ~L., British Army, a distinguished and 



