A^ov. 4, 1 886] 



NA TURE 



out of the five cases it was dust alone. In four out of the 

 five cases the immediate cause was shot-firing, but in no 

 instance was the shot bloii'n out. It is not at all necessary 

 that the shot should be blown out to cause the ignition 

 of the dust-clcud which the concussion raises in a dusty 

 road. Properly fired shots show flame even when they 

 dislodge the stone or coal ; and the flame is often con- 

 siderable if there has been an overcharge of powder, or if 

 small coal or earth mixed with coal-dust has been used, 

 as frequently happens, in the tamping. At Seaham, 

 Tudhoe, West Stanley, and Usworth the flame of the 

 shot ignited the dry inflammable dust dislodged from the 

 roof or raided from the floor by the concussion of air 

 which followed, and the explosion was propagated by 

 fresh dust-clouds raised in the manner described by the 

 Royal Commissioners. At Trimdon Grange an explosion 

 of fire-damp operated in the same way : the violent move- 

 ment of air resulting from the ignition of fire-damp and 

 air raised a cloud of coal-dust into which the fl.ime from 

 the fire-damp passed, and the ignition of the coal-dust 

 propagated itself as in the other cases, and, as in these, 

 continued so long as it was fed by fresh fuel. This rapid 

 ignition of dust containing upwards of 80 per cent, of 

 carbon would result in the formation of large quantities 

 of carbonic acid, and possibly even of the more poisonous 

 carbonic oxide : when it is considered that it is impossible 

 to live in air containing even 3^ per cent, of carbonic acid, 

 the deadly character of the after-damp so formed is 

 readily conceivable. 



In striking contrast to the Durham explosions was that 

 at Whitehaven. This was in a wet pit ; the coal being 

 worked was wet, and all the surroundings were damp, and 

 free from dust. The cause of the explosion was gas, 

 which was known to be in the pit, and frequently present 

 in large quantities. Although it is probable that some 

 30,000 cubic feet of an inflammable mixture of air and 

 fire-damp were ignited, the explosion was confined to a 

 limited area of the workings, which extend to nearly three 

 miles from the shafts. Seven men were within the district 

 of the explosion, of whom three escaped. The survivors 

 stated that all the men were alarmed by the appearance 

 of gas immediately before the explosion, and hurried 

 away. In the act of retreating the gas ignited at a lamp 

 which was afterwards proved to have been defective and 

 to allow of the passage of the flame. This the authors 

 say was the most considerable explosion of fire-damp and 

 air that they are acquainted with. They have personally 

 investigated during the last twelve years almost all the 

 explosions occurring in the North of England, and they 

 cannot point to a case where there was direct evidence of 

 so large a quantity of fire-damp and air exploding. 



The moral of all this is obvious. It can scarcely be 

 gainsaid that some of the most disastrous explosions of 

 the last thirty years are primarily to be attributed to the 

 practice of firing gunpowder in dusty mines. That under 

 certain circumstances gunpowder can be used with safety 

 is allowed. But the Royal Commissioners have issued a 

 warning in no uncertain terms. They have convinced 

 themselves that the abolition of the use of powder in dry 

 and dusty mines will not generally involve any formidable 

 inconvenience, inasmuch as the work which is accom- 

 plished by its employment both in coal and in stone can 

 now be performed with equal efficiency, and at very little 



if any greater outlay, by other means. Unless, therefore, 

 mining engineers, or those immediately responsible for 

 the working of collieries, can devise some satisfactory 

 method of minimising the danger due to dust, they will be 

 compelled before very long, in deference to public opinion, 

 to renounce the practice of blasting by means of gun- 

 powder, or by any other agent which causes a flame. 



T. E. Thorpe 



McLENNAN'S "STUDIES IN ANCIE.XT 

 HISTORY" 

 Studies in Ancient History : comprising a Reprint of 

 " Primitive Marriage." By the late John Ferguson 

 McLennan. A New Edition. (London : i\Iacmillan 

 and Co, 1886.) 



THE first edition of " Primitive Marriage " appeared 

 in 1865, and the book was already extremely rare 

 when, in 1876, it was reprinted as the first part of the 

 " Studies in Ancient History." The reprint also soon 

 became scarce, and while the influence of the author has 

 been steadily growing, and almost all students of early 

 society have come to attach great importance to his 

 speculations, his principal writings have for some years 

 been almost inaccessible. This new edition therefore sup- 

 plies a real want, and it is doubly welcome for the sparing, 

 but judicious, notes and appendixes which the editor, 

 Mr. D. McLennan, has attached to his brother's book. 

 "Primitive Marriage" broke ground in a new field of 

 research, and, as the point of view was wholly novel, the 

 collection, sifting, and marshalling of the evidence on 

 which the argument was based was entirely pioneer's 

 work. At the close of his life, McLennan was in posses- 

 sion of a much larger material ; he had pursued his argu- 

 ment in new directions and to further conclusions, and on 

 one or two points he had come to change his views. But 

 new research had only confirmed the main lines of the 

 argument sketched with so firm a hand in his original 

 essay ; and read with the caveats which his brother has 

 introduced at one or two points — chiefly as regards the 

 interpretation of the Levitate, and the prevalence of Ag- 

 nation — the present reprint may be taken as generally 

 representing, so far as it goes, the author's final conclu- 

 sions on the subjects discussed. I say so far as it goes, 

 for in many directions his conclusions had been added to 

 and his views developed. The editor promises us a 

 second volume, to consist for the most part of writings 

 hitherto unpublished, which will throw a good deal of 

 light on these new developments ; meanwhile he has re- 

 stricted himself in the notes " to certain matters on which 

 the author had announced a change of view, and to cer- 

 tain others where circumstances had made an additional 

 statement imperative." Of the additional statements, the 

 most important is contained in two long notes appended 

 to the essay on Morgan's " classificatory system " of re- 

 lationships, in which it is clearly made out that Morgan's 

 theory rests on misconception of the facts, and that the 

 supposed classificatory system of relationship is not a 

 system of relationship at all, but a system of terms of 

 ceremonial or friendly address, used in conversation even 

 between persons who are not related to one another in 

 any way. This comes out so clearly in the cases about 

 which we are best informed, that it is very questionable 



