PKOGKESS IN" EXPLOSIVES GUTTMANN. 267 



Chlorate mixtures have at all times fascinated inventors on account 

 of the large amount of oxygen stored up in potassium chlorate, which 

 can be given off so readily. When Lavoisier and Berthollet tried to 

 make a chlorate powder in a stamp mill in 1788, they made a great 

 show of it, and even two ladies were present. Unfortunately after 

 a certain amount of pounding the powder exploded and killed an 

 official and the daughter of the government commissary, who assisted 

 at the experiments. 



In this country we have for a long time refrained from licensing 

 any explosive containing potassium chlorate, because such are so 



sily exploded by impact or friction. With the advent of electro- 

 lytic methods for the manufacture of chlorine, potassium chlorate, 

 and the like, chlorate explosives were brought within easy reach of 

 the trade, and in fact the present price of electrolytic potassium 

 chlorate will under certain conditions permit the economical manu- 

 facture of suitable explosives. Hence greater efforts were made to 

 render chlorate explosives more stable, so as to pass the home office 

 test, and ultimately success was attained by the addition of some oil. 

 Its function is evidently to so surround the potassium chlorate that, 

 when mixed with carbonaceous matter, it becomes less sensitive. 

 The addition of greasy matter to chlorate explosives is not at all a 

 new idea. In 1867 already F. Hahn added spermaceti to a gun- 

 powder containing chlorate.'^ However, a practical explosive was 

 ultimately obtained in cheddite, patented by Mr. Street,^ and so 

 called because it was first made in Chedd, in Switzerland. The more 

 usual variety is known abroad under the name of cheddite 60 bis, 

 and its composition is 80 parts of potassium chlorate, 13 parts of 

 mononitronaphthalene, 2 parts of dinitrotoluene and 5 parts of castor 

 oil, whilst in this country the proportions of mononitronaphthalene 

 and dinitrotoluene are reversed. 



It is interesting to observe how the same old mixtures are proposed 

 over and over again with slight alterations only, in order to qualify 

 for a patent. Potassium chlorate with some carbonaceous matter 

 like charcoal, sugar, starch, glycerin, flour, or sometimes a vegetable 

 or mineral oil and the like occurs again and again. One patent '^ is 

 of special historical interest, since it proposes the use of " Maltha " 

 as an ingredient. The patentees came from California, an English- 

 speaking country, and therefore it might be supposed that the name 

 was not unfamiliar in England, but this appears not to be the case. 

 I recollected, however, a passage in Roger Bacon's " Opus Ma jus " 

 as follows : " Nam Malta, quae est genus bituminis et est in magna 

 copia in hoc mundo, proiecta super hominem armatum comburit 



« British patent No, 960, of 1867. 



6 Id,, No. 9970, of 1897, 



<' Quiuby, Sharps aud Greger, British pateut No, 4781, of 1902, 



