674 
NATURE 
[AUGUST 19, 1915 


and dried botanical specimens. The Surveyor- 
General expresses a hope that these explorations on 
the Northern Assam frontier will be continued, and 
is of opinion that with tact and precaution all difficul- 
ties in the way of visiting and exploring the narrow 
strip of hills between the Assam valley and Tibet may 
be overcome.” 
As to the natural history work, there was pub- 
lished :— 
III. Journal Asiatic Society of Bengal, vol. xliv., 
part ii., 1875: Notes on the Geology of part of the 
Dafla Hills, Assam; lately visited by the Force under 
Brigadier-General Stafford, C.B., by Major H. H. 
Godwin-Austen, F.R.G.S., F.Z.S., etc., Deputy 
Superintendent Topographical Survey of India, with 
map. Plate ix. 
IV. Journal Asiatic Society of Bengal, vol. xlv., 
part ii., 1876: On the Helicide collected during the 
Expedition into the Dafla Hills, Assam, with 
plate viii., p. 311. 
V. On the Cyclostomacea of the Dafla Hills, Assam, 
p- 171, with plates vii. and viii. a. 
VI. List of the Birds collected on the Expedition into 
the Dafla Hills, Assam, together with those obtained 
in the adjacent Darrang Terai, with plates iii. and 
iv., p. 64, by same author. 
H. H. Gopwin-AustTeENn. 

Moustier Implements and Human Bones in Suffolk. 
Owinc to the liberality of the trustees of the Percy 
Sladen Memorial Fund, I have been enabled during 
the past eighteen months to conduct a continuous 
series of excavations in the south-west corner of 
Messrs. Bolton and* Laughlin’s briclfield, Ipswich, 
where a well-marked “ occupation-level” occurs rest- 
ing upon a weathered surface of chalky boulder clay, 
and covered by a very hard and compact sandy loam 
of a greyish colour. It appears that since the people 
lived who occupied this ‘‘ floor’ the valley, which is 
now dry, has been deepened considerably, and as 
the “floor” passes into a small escarpment to the 
south at a depth of about to to 12 ft. from the surface 
of the ground, it seems that a considerable antiquity 
must be assigned to the human relics associated 
with it. The occupation-level under investigation is 
very rich in flint implements, which, in my opinion, 
must be assigned to the Moustier epoch. (Traces of 
another occupation-level occur above the Moustier 
deposit, containing implements of a totally different 
type which approximate to the earlier Aurignac 
examples.) With the flints have been found several 
hundreds of animal bones, representing chiefly the 
remains of the horse, and one specimen referable to 
the mammoth. Numerous fragments of very rough 
and primitive pottery occur in the floor, and tend 
to support Dr. Rutot’s claim that about five hundred 
fragments of pottery were found at Caillou-qui-Bique, 
associated with an upper Le Moustier industry. 
Three portions of the human skeleton have been found 
scattered upon the ‘floor’ with the flints and mam- 
malian bones. These comprise a small portion of the 
upper margin of the occipital bone of a skull 10 mm. 
in thickness, the shaft of the left humerus of a 
woman, and the shaft of the right femur of a man. 
There seems little doubt that any of the bones found 
belonged to individuals of the Neanderthal race. All 
the human and animal bones are well preserved and 
in a condition of fossilisation. The excavations are 
still in progress, and it is hoped that further dis- 
coveries will be made. J. Rem Morr. 
12 St. Edmund’s Road, Ipswich, August 13. 
NO. 2390, VOL. 95| 

THE GAS INDUSTRY AND EXPLOSIVES. 
HE need that has arisen for certain coal-tar 
products for the manufacture by nitration of 
the high explosives essential in the present war, has 
riveted attention on the best methods for obtain- 
ing these, and of keeping up the supply to the 
highest possible amount during the period of 
hostilities. 
The substances most needed are the aromatic 
hydrocarbons, of which benzene forms the base 
from which the newest and most powerful of these 
explosives, tetranitroaniline, is prepared, and also 
the tetranitromethylaniline, which under the name 
of “tetryl” is playing an important part in detona- 
tors and primers. Toluene, the next member of 
the aromatic group, is needed in enormous quanti- 
ties to nitrate to trinitrotoluene, or T.N.T., whilst 
carbolic acid is the base from which picric acid 
is formed, this body under slightly varying condi- 
tions being the English explosive lyddite, the 
French melinite, and the Japanese shimose powder. 
The aromatic hydrocarbons found in the coal-tar 
are only a small proportion of those existing in 
the gas, as the volatility of the so-called benzols— 
benzene, toluene, and xylene—causes the largest 
proportion of them to be carried forward as 
vapour in the coal gas, and on cooling this gas 
and scrubbing it with creosote oil a much larger 
yield is obtained from the gas than from the tar. 
The formation of these bodies is due to the action 
of heat on the primary constituents of the decom- 
position of the coal, and when coal is distilled at 
very low temperatures the primary products of 
the decomposition, which largely partake of the 
character of paraffins, 7.e., saturated hydro- 
carbons, are found, whilst the aromatic hydro- 
carbons are to all intents and purposes absent. 
As the temperature of carbonisation is raised, the 
paraffin hydrocarbons become less in quantity, 
and naphthenes make their appearance in the tar. 
At still higher temperatures, these naphthenes 
split off hydrogen and become converted into 
aromatic hydrocarbons, such naphthenes as 
hexahydrobenzene being converted into benzene 
with evolution of hydrogen. As the temperature 
of carbonisation is still further increased, the 
tendency is for these bodies to become converted 
into naphthalene, whilst the employment of very 
high temperatures with light charges gives rise to 
a tar which contains only very small traces of 
aromatic hydrocarbons, large quantities of naph- 
thalene, and a very large proportion of free 
carbon, produced by the degradation by heat of 
the other hydrocarbons present. 
When, however, vertical retorts and heavy 
charges with horizontal retorts were introduced, 
a marked improvement in the quality of the tar 
took place: the heat from the walls of the retort 
passing slowly into the mass of coal distilled off 
the tar vapours at the lowest possible tempera- 
ture, and these, finding an exit through the com- 
paratively cool core of the coal to the mouthpiece, 
a large proportion of the lowest temperature tar 
was produced. As the charge became more and 

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