180 
alteration of these rocks as a concomitant of the 
leaching that collected the filling material. But the 
ascensionists, whether belonging to the school of Elie 
de Beaumont and Durocher or to that of Stelzner and 
Posepny, recognised that the solutions from which 
the materials of the lode were precipitated, whether 
gaseous or liquid, also penetrated the walls and there 
caused certain deposits in the rock itself—metallic ores 
taking the place of some other mineral dissolved, as, 
for example, when cassiterite forms pseudomorphs 
after feldspar in the granite country of tin-veins. 
Much evidence favouring the latter view has since 
been accumulated. Thus Posepny described in 1873 
the replacement of carbonate of calcium by carbonate 
of zinc in the Raibl deposits; and Pumpelly in the 
same year attributed the origin of the native copper 
of the famous Michigan deposits to metasomatic pro- 
cesses. 
In 1881 Emmons showed that the Leadville silver- 
lead deposits had been formed by the replacement of 
limestone by galena, blende and pyrites, an alteration 
which, although chemically complete, left untouched 
the granular texture, joints, and other structural 
features of the original limestone. He pointed out 
that the resemblance of the altered rock to limestone 
was so perfect that, when the faces of the drifts were 
covered with dust, the observer was often completely 
deceived until the breaking of a fresh fragment with 
the hammer revealed the metallic gleam of galena 
beneath. 
In a later paper he showed that many so-called 
fissure veins were not true cavity-fillings, but owed 
their origin to the metasomatic replacement of the 
rock material by substances brought in by solutions 
circulating along fault-fissures, through crush-zones 
or in sheeted zones. In such cases a vein may be 
formed by the replacement of the material enclosed 
between adjacent parallel fractures, true cavity-filling 
being only of a restricted character. Owing to the 
difference in character between replaced sheets of 
country rock and the filling of the fissures that divide 
them, deposits formed in this way sometimes possess 
a banded structure, which, however, is distinguishable 
from the normal “crustification ’’ of vein-fillings. The 
whole subject has been admirably reviewed by Lind- 
gren and by J. D. Irving in their well-known papers, 
in which will be found many illustrations of the 
potency of metasomatic processes in vein-formation. 
Modern views on ore-genesis may be reduced to two 
principal lines of inquiry, one dealing with the 
agent or vehicle by which the metals have been col- 
lected, conveyed to, and deposited in the places where 
they are now found, and the other with the nature 
of the concentrates formed in the course of these 
processes. 
Considering the latter first, ore-deposits are found 
to be either :—(1) Igneous differentiates; (2) cavity- 
fillings; (3) metasomatic replacements; (4) stratified 
or sedimentary deposits; (5) residual deposits. Of 
these, the sedimentary deposits comprise marine, 
lacustrine, and fluviatile accumulations, including 
placers. 
Coming now to the agents or vehicles of ore-concen- 
tration, these are found to be :—(a) Molten magmas; 
(b) gases and vapours above their critical temperature; 
(c) deep-seated waters, whether of magmatic or of 
meteoric origin; (d) vadose waters; (e) chemical and 
bacterial agents in lakes and seas; (f) mechanical 
agents, such as moving water and wind, 
It is possible, by combining the facts elicited by 
these two lines of inquiry, to formulate a genetic 
scheme of classification. For example, cavity-filling 
may be due to igneous injection, to gases and vapours 
above their critical temperatures, to deep-seated waters, 
or to vadose waters; again, metasomatic replacement 
NO. 2320, VOL. 93| 
NATURE 
[APRIL 16, 1914 
may be brough: about by gases and vapours, by deep- 
seated waters, or by vadose waters. By arranging 
these two series of relationships in vertical and hori- 
zontal columns respectively, all the various types of 
ore-deposits are obtained at their intersections; and 
in this way the classification shown in the table on 
p- 179 is obtained. 
UNIVERSITY AND EDUCATIONAL 
INTELLIGENCE. 
It is announced in Science that provisions for the 
creation of a trust fund, said to be approximately 
100,000l., for the maintenance of male graduates of 
the Williamsport, Pa., high school at Corn<‘l Univer- 
sity are made by the will of Mr. A. D. Hermance. 
From the same source we learn that Mr. E. Palmer, 
a Princeton graduate, has offered to build and present 
to Princeton University a stadium costing 60,o000l. 
Mr. Palmer is a son of the late Mr. Stephen S. 
Palmer, who was for many years a trustee of Prince- 
ton University, and gave large sums to the Univer- 
sity, including the Palmer Physical Laboratory. 
Many important recommendations are made in the 
report of the Royal Commission on the Civil Service 
just issued as a Blue-book (Cd. 7338). It is proposed 
to abolish the grades known as the Second Division, 
the Intermediate Class, the Assistant Clerks, and the 
Boy Clerks, and to substitute for them a new class, 
to be known as the Junior Clerical Class, to be 
recruited at the age of sixteen, at which many boys 
leave the public secondary schools. Another new class 
recommended is the Senior Clerical Class, to be 
recruited at the age of eighteen. In both cases the 
examinations for appointments in these grades are to 
be brought into close relation with the work of the 
schools. Other recommendations are :—(1) Greater 
facilities should be provided, especially in England 
and Ireland, for the progress from the primary to 
the secondary schools, and thence to the universities, 
of pupils capable of benefiting by secondary and uni- 
versity training respectively. (2) There should be 
closer coordination between the educational systems 
of the country and the Civil Service Examinations, 
and to this end the Treasury and the Civil Service 
Commissioners should consult more freely and 
systematically than hitherto with the Departments 
of Education before framing examination schemes. 
(3) The principle of open competition should be adhered 
to, and whenever it is applicable, extended. (4) The 
competitive examinations for recruiting each class of 
officer, administrative and clerical, should be adjusted 
in respect of the age of competitors and the subjects of 
competition to the stages of the educational system 
actually. existing in the country. (5) The examina- 
tions should be directed to testing the natural ability 
of candidates, and the results of their education both 
with respect to acquirement of knowledge and the 
formation of mind and character. It should not be 
directed to testing proficiency in particular subjects 
which lie outside the normal scope of education. 
SOCIETIES AND ACADEMIES. 
LONDON. 
Linnean Society, April 2.—Dr. A. Smith Woodward, 
vice-president, in the chair.—W. Rushton: Structure 
of the wood of Himalayan Junipers.—W. B. Turrill : 
A contribution to the flora of Fiji.—Prof. C. Chilton : 
A new Amphipodan genus and_ species (family 
Dexaminidz) from New Zealand.—Prof. E. B. 
Poulton: Mr. W. A. Lambourn’s breeding experiments 
upon Acraea encedon (Linn.), Poulton, in the Lagos 
district of West Africa, 1910-12. 
