14 



SCIENCE, 



[Yol. IV., No. 74. 



The variations from the above composition have 

 consisted in varying the proportions given, in the ad- 

 dition of camphor, benzene, and the like substances 

 to increase the insensibility, and of oxidizing and 

 combustible agents to cheapen the cost and modify 

 the force of the explosive. The widest departure 

 from the original explosive gelatine is probably found 

 in the substance styled ' forcite,' invented by J. M. 

 Lewin. This is made by subjecting finely powdered 

 paper stock, or other form of cellulose, to the action 

 of high-pressure steam until the cellulose is converted 

 into a gelatinous mass. This is then cooled and im- 

 mersed in water, where it preserves its gelatinous 

 form indefinitely. Seven parts of this gelatinized 

 cellulose, seventy-five parts of nitroglycerine, and 

 eighteen parts of nitre are incorporated together over 

 a water-bath at a temperature of 40° C. The result is 

 a whitish, opaque, gelatinous mass. The ingredients 

 are varied by substituting dextrine and ordinary 

 cellulose for a part of the gelatinized cellulose. 

 Judging from some of the descriptions of this powder, 

 various coloring-matters are also used. It is claimed 

 for this explosive, that while it is stable, and holds its 

 nitroglycerine so firmly that it is not separated by 

 sulphuric ether, alcohol, or water, and while it burns 

 in the open air without explosion, yet it may be ex- 

 ploded in a drill-hole by ordinary fuses. Three fac- 

 tories are now producing this explosive in Europe, 

 and one has recently been started on a very extensive 

 scale in New Jersey. These last works are stated to 

 have a capacity of five tons of powder per day. A 

 novelty in these works is the use of India-rubber 

 pipes laid underground for conveying the nitroglycer- 

 ine from the converting-house to the incorporating- 

 houses. 



Among the processes invented for making nitro- 

 glycerine, the one devised by Boutmy and Faucher 

 seemed to offer the best assurance of safety, owing 

 to the absence of all energetic action during the 

 operation of conversion. In this process nitric and 

 sulphuric acids were mixed together in equal propor- 

 tions. A second mixture was then made, with one 

 part of glycerine to three and two-tenths parts of 

 sulphuric acid. When quite cooled, fifty-six parts 

 of the first mixture were mixed in an earthenware 

 vessel with forty-two parts of the second mixture, 

 and allowed to remain from ten to twenty-four hours, 

 when the nitroglycerine was found to have formed 

 quietly, and collected more or less completely on the 

 top of the acids. The failure of the nitroglycerine 

 to separate completely and at once from the acids 

 has been pointed out as a source of danger in the 

 process, since nitroglycerine is decomposed through 

 prolonged contact with strong acids. In spite of this, 

 the process has been in use at the French govern- 

 ment factory at Yonges since 1872, and but one 

 accident is recorded. They dealt, however, with com- 

 paratively limited quantities, and used pure materials. 

 Probably the first attempt to apply the process on 

 a commercial scale was made at Pembrey, in Wales, 

 in 1882, where an iron converter was constructed for 

 nitrating fifteen hundred pounds of glycerine in each 

 charge. The process of mixing differed from that 



used at Yonges, in that, while the final mixing was 

 done there by hand with a wooden paddle, at Pem- 

 brey the sulphoglycerine mixture was blown into 

 the acid mixture in the form of a spray, while the 

 acid mixture was being agitated by a blast of air. The 

 process, as thus modified, had been in operation but 

 a few months, when the converter, while containing 

 from five hundred to six hundred pounds of nitro- 

 glycerine, was blown up. Col. Majendie has given 

 an extended account of the circumstances in his re- 

 port, No. 48, to the home secretary; and he considers 

 the explosion due to violent chemical action, estab- 

 lished in acid nitroglycerine present in the converter. 

 Dr. Dupre, however, found the glycerine used to be 

 contaminated with fatty acids, while no effort had 

 been made to free the nitric acid from nitrous acid. 

 This lack of care would have led to danger in any 

 process. 



Some years since, Dr. Sprengel proposed a conven- 

 ient and safe way of forming explosives by using 

 oxidizing and combustible agents of such a nature 

 that they could be readily mixed at the place where 

 wanted for use. Several such mixtures have been 

 devised; among others, ' rackarock,' which consists of 

 potassium chlorate and nitro-benzene, and which has 

 given good results. For this explosive the chlorate is 

 furnished in bags of suitable size ; and, when wanted 

 for use, these bags are immersed in the liquid nitro- 

 benzene for a determined length of time, when they 

 are ready to be exploded. The most recent explosive 

 of this class, 'panclastite,' is composed of liquid 

 nitrogen tetroxide and a combustible agent, prefera- 

 bly carbon disulphide, in the proportion of three vol- 

 umes of the first liquid to two of the second. The 

 heat developed by the combustion of this mixture is 

 estimated at about 3000° C. ; and, when burning freely, 

 the light is so bright as to equal that of the calcium 

 light. The inventor claims that its explosive power, 

 when confined, surpasses that of dynamite ; but the 

 French explosive commission, when using Abel's lead 

 cylinder test, obtained a slightly less value. With' 

 a mixture of equal volumes of nitrogen tetroxide and 

 of nitrotoluene, however, they obtained the same 

 value as for dynamite No. 1. Notwithstanding the 

 power of the panclastite mixtures, it is questionable 

 whether such a substance as nitrogen tetroxide can 

 be brought into any general use. 



While much attention has been given to the high 

 explosives, the claims of gunpowder have not been 

 overlooked; and many changes have been proposed 

 in the form, size, shape, and density of the grain, 

 and in the mode of manufacture and composition of 

 the mixture. The most novel among these is the 

 hydrocarbon-powder, made from a mixture of nitre 

 or potassium chlorate with a solid hydrocarbon, such 

 as paraffine, asphaltum, India-rubber, and the like. 

 The incorporation is effected by the aid of a volatile 

 liquid solvent, which dissolves the hydrocarbon, and 

 furnishes a plastic mass, which may be moulded into 

 any desired form, and then hardened by allowing the 

 solvent to evaporate. A peculiar advantage claimed 

 for the powder is its imperviousness to water. 



A variety of gunpowder made by the Rottweil- 



