498 



[NATURE 



[April 22, 1875 



ACCIDENTAL EXPLOSIONS* 

 III. 

 A FEW substances well known to chemists are so very unstable 

 ■'^ in character, or are so very difficult to prepare in a condition 

 approaching purity, that they either begin to undergo change as 

 soon as they have been produced, or very shortly afterwards, 

 such change proceeding sometimes gradually and quietly until 

 the substance has been transformed into non- explosive bodies, 

 or occurring;, in other instances, with a rapidity speedily resulting 

 in the violent decomposition or explosion of the substance. 

 Injuries more or less severe have been inflicted upon the dis- 

 coverers or investigators of substances of this kind, or upon those 

 who prepare them and exhibit their properties for instructional 

 purposes, and such accidents occasionally occur even though all 

 possible or reasonable precautions appear to have been taken to 

 guard against them. It has occasionally also hajspened that 

 serious accidents have resulted from attempts to apply to prac- 

 tical purposes the explosive power of such substances (as, for 

 example, the chloride of nitrogen and iodide of nitrogen) by 

 persons imperfectly acquainted with their properties or those of 

 explosive substances generally. The great danger in which want 

 of knowledge may involve experimenters in this direction is too 

 obvious to need being dwelt upon. 



The risk of accident resulting from the liability of explosive 

 compounds to so-called spontaneous decomposition has been on 

 several occasions exemplified in the past history of the two most 

 important of these compounds, gun-cotton and nitro-glycerine. 

 The stability of properly purified gun-cotton, as well as that of 

 nitro-glycerine, have, however, now been for some time past fully 

 established, and no difficulty exists in carrying on with safety 

 their manufacture on such a scale as to satisfy the continually 

 increasing demand for efficient preparations of these violent 

 explosive agents. At the same time the experience of the last 

 few years has aflbrded repeated illustrations of the terrible risks 

 and responsibilities incurred by manufacturers of these substances 

 by the slightest departure from conditions essential to perfection 

 and safety of manufacture, or by a relaxation of the strictest 

 supervision in the production, purification, and storage of the 

 materials. 



In these respects the utilisation of explosive compounds of 

 this class involves special risks not aitendant upon the manufac- 

 ture of gunpowder and modifications of that substance ; in 

 others, however, it presents important elements of comparative 

 safety. For example, the manufacture and purification of gun- 

 cotton, and its conversion into the compressed or granulated 

 substance, are absolutely safe operations, the material being wet 

 throughout the entire course, and therefore quite uninllammable, 

 until, when completed, it is dried by long exposure to air, or by 

 artificial heat. On the other hand, gunpowder, and all prepara- 

 tions of similar nature, are explosive from the very commence- 

 ment of their manufacture. 



Accidents at gunpowder factories are very frequent, and 

 though they may not often involve considerable loss of life or 

 destruction of property, the fact that their occurrence must in 

 most instances be caused by partial, occasional, or complete and 

 persistent neglect of precautions absolutely essential to the safety 

 of the people employed in the works, or to a reduction of the 

 risks of accident to the minimum, points to the necessity for 

 improved legislation connected with manufactories of gunpowder 

 and other explosive preparations, whereby the proper attention 

 to regulations and precautions for safety may be rendered com- 

 pulsory, and seconded by an efficient system of inspection. 



After stating a number of precautions that ought to be adopted 

 in all gunpowder manufactories, Prof. Abel said that lastly, 

 though properly first in importance, the manufacturers of gun- 

 powder and other explosive agents should not only themselves 

 possess some scientific as well as a practical knowledge of the 

 nature and properties of the substances in the manulacture of 

 which the lives of their workmen are at stake, but they also 

 should ascertain and insist that at any rate the persons who act as 

 managers and foremen in their factories should not be deficient 

 in the elementary knowledge indispensable to a proper perform- 

 ance of their duties. 



Major Majendie, the Government Inspector of Gunpowder 

 Works, &c., has reported officially that he was " much struck, 

 in the course of his inspections, with the extraordinary ignorance 

 of even the most elementary dangers, and the precautions neces- 



* Abstract of a lecture delivered at the Royal Institution, March j2, 

 by Prof. F. A. Abel, F.R.S. Continued from p. 478. 



sary for avoiding them, which prevails among persons in charge 

 of important factories and magazines," and that there can be no j 

 doubt that to the ignorance and incompetence of such persons a \ 

 large number of the accidents which occur are indirectly due. « 

 Surely it is in the interest of employers to adopt measures for ■ 

 securing that the management of their works is in the hands of | 

 competent men, experienced in the details of the m.anufacture, j 

 and possessing adequate general education and technical know- 

 ledge to fit them for posts of such responsibility. The obvious | 

 mode of securing this is to render it compulsory for such men to ; 

 obtain certificates of competency before they can hold re!-ponsible 1 

 appointments in manufactories of gunpowder and other explosive 1 

 agents. , 



The manufacture of fireworks, ammunition, percussion caps, 

 and other articles involving the application of explosive agents 

 is, it need scarcely be stated, attended by liability to accidents 

 similar to and sometimes even greater than that existing in manu- 

 factories of gunpowder and materials of similar nature, and 

 necessitates the adoption of precautions ot the same nature ag 

 apply to these works. 



Such necessity has, however, been very much disregarded in 

 the arrangement and management of factories of this kind, and 

 many very sad casualties have resulted either from utterly inade- 

 quate arrangements for localising explosions and reducing them 

 to small proportions, by regulating the quantities of material 

 dealt with in one building, and sutBciently separating and sub- 

 dividing the manufacturing operations, or from neglect of simple 

 regulations for excluding sources of fire from the buildings. 



There are several important instances of accidental explosions 

 on record which have occurred in the manufacture of pyrotechnic 

 compositions and other articles of explosive nature, in conse- 

 quence of a liability to the establishment of chemical activity 

 between the ingredients of such preparations by even very slight 

 inciting causes. Thus, certain descriptions of coloured fires are 

 readily susceptible of so-called sponraneous ignition or explosion, 

 either simply from the unstable nature of one or other of their 

 ingredients, or from so apparently trifling a cause as the absorp- 

 tion of a small amount of moisture, or the employment of a 

 small quantity of an easily oxidisable oil or fat in connection 

 with their application to pyrotechnic purposes. In one in- 

 stance, some signal lights, composed of a mixture of ingre- 

 dients which long experience had shown to be in every way as 

 permanent as those of gunpowder, were found to be undergoing 

 decomposition to an extent which, had it not been noticed in time, 

 must have resulted in serious consequences. The cause of this 

 change baftlsd inquiry for some time, but ultimately it was clearly 

 established that a very minute quantity of free acid contained in 

 the paper linings of the cases in which the composition was 

 confined (and derived from the antichlore used in the manufac- 

 ture of the paper) had set up an action between the saltpetre and 

 the orpiment composing this material, which spread gradually 

 but with increasing rapidity through the highly compressed mass, 

 being of course accelerated by the heat developed. 



After referring to the great dangers arising from the manufac* 

 ture of fireworks in dwelling-houses of the lower classes in 

 crowded districts, the lecturer said that the fearful recklessness 

 with which gunpowder and other explosi'/e agents are handled 

 and used by uneducated persons, such as these small firework 

 makers, of which there are large numbers in the mining and 

 manufacturing districts, and by the most extensive consumers of 

 powder, namely, the miners and quarrymen, can scarcely be 

 realised by anyone who has not had opportunity to acquire by 

 personal observation a knowledge of the state of things. 



Prof. Abel then gave instances of the incredible carelessness 

 frequently shown by miners in their preparations for blasting 

 both with gunpowder, gun-cotton, dynamite, and other explosive 

 substances. 



It is, however, more particularly from the fact that there are 

 no regulations forbidding or restricting the making up, in dwell- 

 ing-houses, of blasting cartridges, mining fuses, and the so-called 

 powder straws used in blasting, that the chief liability to acci- 

 dental explosions in mining districts arises. Miners are constantly 

 in the habit of keeping considerable quantities of powder in 

 their dwelling-rooms, and making up their cartridges or fuses 

 (straws) at night. 



After giving some illustrations of the disastrous results Of 

 carelessness in the handling of gunpowder. Prof. Abel said that 

 it naturally follows that other explosive agents, such as dynamite 

 and gun-cotton, should be treated with similar and perhaps even 

 greater recklessness. The apparently less dangerous nature of 



