234 



SCIENTIFIC NEWS. 



[Dec. 1st, li 



observed in practice was accepted, not merely as a fact, but 

 rather as an illustration of some pathological doctrine of 

 the time. Mercury was, at different times, an antiphlogistic, 

 a depurative, an alternative, and I know not what besides — 

 harmless words if they had not been used as facts ; but be- 

 cause it was thought, not known, to be all these and more, 

 it was so misused and did so much harm that it nearly lost 

 all its just repute, and many disused it. Similarly, bleeding 

 was practised in excess, not so much because of the good it 

 sometimes did, as because the physiology of the time seemed 

 to prove that it must be useful in a large number of condi- 

 tions in which it was not. And because this was deemed 

 sure, men overlooked the evidence that it was often useless 

 and sometimes mischievous ; they did not observe ; they 

 preferred thinking, and they thought erroneously, and were 

 guided by their thoughts more than by the facts. Now, 

 these were errors of men as honest and as clear-headed as 

 any in our own day, and among them were some to whom 

 medicine owes great help to progress. Surely it should 

 make us very cautious. I have cited old historic errors, but 

 exactly similar modes of thinking are everywhere prevalent, 

 exactly similar fallacies in letting doctrines rather than facts 

 serve as our guides in practice. And we need the more 

 caution because this assumed power of explanation is so 

 much more attractive than the gathering of facts. The ex- 

 planations are so much more our own ; like very parts of 

 ourselves ; so much more impressive ; they sound so 

 learned, patients admire them —some, I have often thought, 

 would rather have their maladies explained than have them 

 cured. 



Only learn to study after the right manner, and, as all 

 who have had experience in it will tell you, you will find it 

 a source of very rare happiness and utility, and of no harm 

 whatever. There are some, indeed, who would lell you 

 that the scientific man is ill-fitted for anything but science ; 

 that he cannot be punctual, business-like, a plain speaker, 

 pious, or I know not what else. It would be difficult to find 

 greater nonsense in any of the books or journals on a 

 modern book-stall. There is nothing that a man may not 

 be at the same time that he is scientific. I would not make 

 light of anything that would hinder you from being busi- 

 ness-like ; for I should have to admit that I have known 

 more failures in our profession through want of this quality 

 than from the want of any other : more than from the 

 utterest want of scientific or even of good practical know- 

 ledge. But the failures were not only among the scientific. 

 Surely I need not say in Manchester that good men of 

 science may be also good men of business ; and what may 

 be seen here may be seen everywhere. If a man of science 

 cannot be business-like, it is the fault of his brain not of his 

 study; he would have been the same in any other pursuit 

 in life. 



THE INSTITUTION OF CIVIL ENGINEERS. 



AT the ordinary meeting on the 15th November Sir F. A. Abel, 

 in a Paper on " Accidents in Mines," Part II., resumed a 

 consideration of the views which have been entertained and 

 challenged regarding the influence of variations in atmospheric 

 pressure upon the liability to a sudden contamination, to a 

 dangerous extent, of the air in a coal mine by firedamp. The 

 careful examination of existing observations and speculations 

 led the late Royal Commission to conclude that, while certain 

 coincidences of fall and rise of barometer with explosions might 

 be selected to support particular views or theories, no general 

 connection had been satisfactorily established between colliery 

 explosions and sudden barometric changes ; and that the official 

 issue to colliery districts of warnings of approaching changes in 

 atmospheric conditions were to be deprecated, as tending to 

 encourage a false sense of security, and to divert attention from 

 other sources of danger which might be more potent. Attention 



was directed to the accumulation of gas, or explosive gas and 

 air- mixture, in the goaves or old working-places, imperfectly 

 filled up with debris, and often inaccessible to anything approach- 

 ing efficient ventilation, of which extensive areas existed in 

 many mines. The possibility of a communication being estab- 

 lished between the gas-laden spaces in such goaves and those 

 parts of adjacent coal-seams or stone strata in which blasting 

 was being carried on, by fissures resulting from settlement of 

 roof or other causes, was pointed out, and it was indicated that 

 even the flame from a "blown-out" shot might, in particular 

 classes of workings, and where inflammable dust existed in 

 abundance, extend to goaves where an explosive mixture of fire- 

 damp and air might lurk. The importance of filling up, as 

 completely as possible, the worked-out places or goaves in 

 localities underground where there was any possibility of fire- 

 damp accumulations being produced, and where they could not 

 be effectually dealt with by the existing ventilating appliances, 

 was therefore insisted upon. 



The influence of coal-dust in extending and aggravating the 

 effects of firedamp explosions, which was first demonstrated by 

 Faraday and Lyell, was next discussed. The fact that, even in 

 the complete absence of firedamp in the air, a sufficient coal- 

 dust deposit in the immediate vicinity of a working, or the 

 employment of coal-dust as tamping, gave rise to a considerable 

 elongation of the flame projected by a "blown-out" powder- 

 shot, had been abundantly demonstrated by many experimenters, 

 and a series of experiments with various descriptions of coal- 

 dust, made upon a scale representingactualpracticeby the Fire- 

 damp Commission of the Prussian Government, had fully con- 

 firmed the conclusions previously arrived at regarding the 

 important part played by coal-dust in mine explosions. This 

 was now so thoroughly recognised that precautionary measures, 

 bearing specifically upon the dangers which might arise in carry- 

 ing on blasting operations in dusty mine-workings, constituted an 

 important feature in the Mines Regulation Act passed last Session. 

 The manner in which the dangers arising from the presence of dry, 

 very fine and inflammable dust in mine-ways and workings were 

 increased by the presence in the air of a proportion of firedamp, 

 so small as to escape detection by the most skilful inspector by 

 searching with a safety-lamp, was described, and the possibility 

 of disastrous explosions resulting from the ignition by a powder- 

 shot of highly inflammable, dry, and exceedingly fine descrip- 

 tions of dust, even in the complete absence of firedamp was 

 indicated. The necessity for removing dust from the workings, 

 supplemented by copious watering, immediately before the firing 

 of a shot, and other precautions, was therefore insisted upon, if 

 powder was to be allowed as the blasting agent in dry and 

 dusty places. The merits of other explosive agents which had 

 been proposed as substitutes for powder were discussed, as also 

 the origin and development of methods extensively tried by the 

 late Royal Commission and others for applying water, in con- 

 junction with the explosive, as a means of extinguishing flame 

 and sparks produced in firing shots. It was shown that, while 

 none of these could be relied upon as a safeguard when powder, 

 or any explosive analogous to powder was employed, the 

 water cartridge (i.e., a. charge of explosive surrounded on all 

 sides by water), as originally devised and made public by the 

 author, and the comparatively simple and even more efficient 

 method of using water in conjunction with a porous body, such 

 as sponge or moss, allowed of the perfectly safe employment of 

 nitro-glycerine preparations, such as dynamite and gelatine- 

 dynamite, and of some other " high explosives " in dusty work- 

 ings ; this was so, even where firedamp was present in small 

 proportion, or where there was a possibility of the emission of 

 gas in considerable proportion. Proposals to employ substances 

 as tamping, or in admixture with the charge, which would evolve 

 vapour of water, or non-combustible gases, when exposed to heat, 

 were viewed unfavourably, inasmuch as the almost instantaneous 

 duration of exposure to heat of such materials, when the shot 

 was fired, would be insufficient to accomplish the desired genera- 

 tion of non- combustible vapours or gases to an extent calculated 

 to exert any important extinguishing effect. The practical ex- 

 perience gained in the employment of compressed lime and 

 water, according to the plan devised by Messrs. Smith and 

 Moore, had demonstrated that this method of getting coal, which 

 was absolutely safe in its nature, admitted of decidedly advan- 

 tageous application in some varieties of coal, though it could by 

 no means be generally substituted for explosive agents. Im- 

 provements, in point of safety, in methods of firing shots were 



