40 
NATURE 
[ NovEMBER 12, 1896 
an hour. In a recent number of the Russian Photographic 
Review, a description is given of the establishment of Arthur 
Schwartz, at Berlin, where illustrations for magazines are printed 
by this method. The bromide paper generally employed is 100 
centimetres wide and a kilometre long. Sometimes a width of 
450 centimetres is used, and full-size photographs of men on 
horseback have been produced. If the negative from which 
prints are required is much less than 100 cm. wide, a row of 
them is arranged; and in this way forty thousand copies of 
cabinet photographs have been printed and finished ready for 
distribution in ten hours. Our Russian contemporary gives a 
photograph printed by the new method, and it is really a very 
brilliant picture. It is stated that the twelve hundred copies 
required for the embellishment of the Rezvzew were absolutely 
identical in tone and detail. 
IN a recent paper communicated to the Academia dei Lincei, 
G. Folgheraiter describes a curious method he has devised for 
obtaining the approximate value of the dip in ancient times, and 
hence deducing the value of the secular variation. In previous 
papers he has shown that clay, if baked in a magnetic field, 
becomes permanently magnetised in such a way that its mag- 
netic axis coincides with the direction of the magnetic field. 
Hence by measuring the direction of the permanent magnetism 
of clay articles, the date of manufacture of which is known, and 
on the assumption that they were placed in a certain position 
when baked, to deduce the value of the dip. With a view 
of testing the value of this method, a series of preliminary 
experiments have been made, by baking a number of cylinders 
and cones of clay in a furnace which was quite free from iron, 
the test-pieces being placed in positions the relation of which 
to the direction of the earth’s magnetism were carefully noted. 
After cooling the baked clay test-pieces were placed, with their 
axes east and west, at a certain distance from a magnetometer, 
and from the magnitude of the deflections produced when the 
objects are rotated into different positions, the direction of the 
permanent magnetism is deduced. The author reseryes an 
account of the results for a future paper. 
ATTENTION has lately been directed to the surgical uses of 
oxygen gas, the treatment consisting essentially in the exposure 
of affected parts to the action of the gas, either pure or diluted 
with purified air. An account of some remarkable results 
obtained by this means is given in a recent number of the 
British Medical Journal, by Mr. George Stoker. Examinations 
of the bacteriological conditions of affected parts before and 
after treatment, show that oxygen has a selective action in 
reference to micro-organisms in the wounds, destroying some and 
encouraging the growth of others. In all healthy and rapidly 
healing wounds certain micro-organisms regarded as favourable 
to recovery are found, while others are regarded as unfavourable 
micro-organisms. Whatever may be the connection between 
the organisms and the state of a wound or sore, it seems to be 
established that when, in a wound treated by oxygen, healing is 
arrested or retarded, there is always a corresponding decrease of 
favourable and increase of unfavourable micro-organisms. If 
the strength of the oxygen bath be increased when this condition 
arises, the character of the micro-organisms from the wound is 
entirely reversed. Oxygen thus encourages the growth of micro- 
organisms characteristic of healing wounds, with the result that 
a cure is rapidly effected. A long and varied experience of the 
oxygen treatment has led Mr. Stoker to conclude that the 
method heals in less time than any other form of treatment, 
allays pain, stops foul discharges, forms a healthy new skin, and 
is far more economical and less expensive than any other form of 
treatment, both as regards suffering and money. 
To the Reve Générale des Sciences, of October 15, Dr. 
Bernard Renault contributes an interesting article entitled 
NO. I41I, VOL. 55] 
“‘Les Bactéries et leur ceuvre Géologique,” in which he comes 
to the following conclusions: (1) That the bones, shells, 
and teeth of animals in Primary times were infested and 
destroyed by bacteria, analogous in their form and size to those 
which, at the present day, produce caries. (2) That formerly 
the remains of plants were invaded by multitudes of bacteria, 
some attacking the membranous cellular tissue, and others the 
thicker portions. Some of the bacteria acted more particularly 
upon the spores contained in the sporangia of ferns; the paren- 
chymatous tissue first disappearing, then the woody fibres, and 
finally the cells of the epidermis. (3) That if nothing occurred 
to arrest the progress of bacteria, every part of plants would 
disappear successively, and only numerous colonies or zoogloea 
formed by micro-organisms would remain visible. (4) That 
these zoogloea often served as centres of attraction for mineral 
matters, amorphous or crystalline, thus producing ooliti¢ or 
spherulitic structures in rocks. (5) That coal contains con- 
siderable quantities of bacteria, which, by causing the forma- 
tion of hydrogen and carbonic acid, have brought cellulose and 
its derivatives to the chemical composition of this combustible.” 
(Even during the preparation of his article, Dr. Renault found 
micrococci and bacilli in coal from Saint Etienne, Commentry 
and Vicoigne, in Tertiary coal, and in the coal of Transylvania. ) 
Dr. Renault suggests that the work of bacteria, which goes on 
in marshes, ponds, &c., was stopped by the rising of water, 
frequent in Primary times, and capable of carrying away plants, 
having undergone a more or less complete transformation in 
lakes of a certain extent, into seas where fermentation became 
impossible owing to their depth. The physical properties of 
coal—density, hardness, tenacity, &c.—have, therefore, he con- 
cludes, only appeared as the result of a slow compression at the 
centre of a permeable medium, the compression being due to 
the various layers which covered the coal. 
Pror. H, B. Dixon and H. Brereton Baker have investi- 
gated the influence of Réntgen rays on some chemical actions, 
butfrom their note, published in the Zvavsactions of the Chemical 
Society, it appears that the results have hitherto been negative. 
The effect was tried on mixtures of carbon monoxide and. 
oxygen (dried and moist), hydrogen and oxygen, carbon mon- 
oxide and chlorine, hydrogen and chlorine, and, lastly, hydrogen 
sulphide and sulphur dioxide (dried). No combination, either 
explosive or gradual, occurred between the gases exposed. The 
combination of chlorine with carbon monoxide and with hydrogen 
is effected by light, but the addition of Rontgen rays did not 
alter the rate of combination. Although the rays cause electric 
discharge from metallic bodies, they appear to have no effect on 
electrolysis. The action on a photographic plate is probably 
caused either directly or by the fluorescence of the film. It is 
not due to fluorescence of the glass, because the deposit of silver 
takes place entirely on the side of the film exposed to the rays. 
THE Royal Meteorological Institute of the Netherlands has: 
recently published a volume containing interesting J/ede- 
deelingen, or extracts from the log-books of Dutch ships navi- 
gating various parts of the world. The extracts include 
noteworthy phenomena relating to atmospheric electricity, 
unusual disturbance of the compass needle, volcanic eruptions 
and earthquakes, icebergs, &c. The first edition of this work 
appeared in 1867 ; in the twenty-nine years which have elapsed, 
a large amount of material has accrued, which made it desirable 
to recast the whole work, rather than issue a supplementary 
volume. It may be worth noting that the present work also 
contains a discussion of meteorological observations made on 
the Congo, and particulars relating to a few places on the coast 
of Lower Guinea. 
In the Zrdian Meteorological Memozrs, vol. vi. part iii,, 1896, 
Mr. J. Eliot publishes an important discussion of the hot winds 
