7O 
NARGKE 
[May 20, 1886 
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conversion into a superphosphate. This may be done by 
mechanical means. But nature has already partially anticipated 
this process, and the result has been a deposit known as “rich 
phosphate,” containing about 25 per cent. of phosphoric acid. 
This occurs in wide cracks and holes in the ordinary phosphatic 
chalk. It usually occurs as a fine sand-like powder, and is 
evidently the result of the action of carbonated waters upon the 
phosphatic chalk, whereby the amount of carbonate of lime is 
reduced. This is especially the case where the phosphatic chalk 
is not protected by the tufaceous chalk of Ciply, but is only 
covered by Tertiary or Quaternary beds. The author calculates 
that each square foot of the phosphatic basin, which he esti- 
mates approximately at 5 miles by 3, contains 355 lbs. of tribasic 
phosphate of lime. Finally, he intimates how the phosphatisa- 
tion of the chalk may have been brought about. 
Physical Society, May 8.—Prof. H. McLeod, F.R.S., Vice- 
President, in the chair.—Mr. W. A. Price was elected a member 
of the Society.—The following communications were read :— 
On a modified form of Wheatstone’s rheostat, by Mr. Shelford 
Bidwell. A wire is coiled upon a non-conducting cylinder as in 
the ordinary forms of rheostat, one end of the wire being in 
contact with the brass axle of the cylinder. A screw is cut upon 
the axle, the pitch being equal to the distance between the con- 
secutive turns of the wire, and this, working in a fixed nut, 
causes the whole cylinder to travel in the direction of its axis. 
A fixed spring bears upon the wire at a convenient point, and 
by the travelling motion of the cylinder this point of contact 
remains fixed in space, and the effect of turning the cylinder is 
to introduce more or less resistance between the spring and the 
brass axle. Binding screws on the base of the instrument are in 
contact with the nut and the bearing spring. Though this 
arrangement has several obvious advantages over the usual forms, 
Mr. Bidwell does not recommend it in cases where it is required 
to introduce a known resistance, but where it is important to 
adjust a resistance to a nicety, or to cause a continuous variation, 
it is of great use.—Prof. Perry, remarking upon the importance 
of being able to vary a resistance gradually, described an instru- 
ment he had used with advantage. A number of plates of gas- 
carbon are placed between two parallel copper plates, one of 
which is fixed and the other adjustable by a screw ; by applying 
pressure by means of the screw the resistance between the plates 
can be varied uniformly and regularly from 2 to 10 ohms, beyond 
which point the increase is very rapid.—On a theorem relating 
to curved diffraction-gratings, by Mr. Walter Baily. In a paper 
read before the Society in January 1883 the author showed that 
if a plane be taken perpendicular to the lines of a curved diffrac- 
tion-grating, and a normal to the grating be taken as the initial 
line, the equation— 
(in which ¢ is the radius of curvature of the grating, and @ is an 
arbitrary constant), gives a curve having the property that if a 
point of light be placed anywhere upon it the curve is the locus 
of the foci of all diffracted rays whether reflected or transmitted. 
In the present investigation d is supposed to be greater than c, 
which allows of the source of light being at infinity. The 
points where the curve given by the above equation cuts the 
normal are called the normal foci. There are two of these, one 
relating to the reflected and the other to the transmitted light, 
the grating being supposed to consist of a number of opaque 
lines in space. It is then shown that if the grating be supposed 
to turn about the line in it intersecting the initial line, the nor- 
mal foci will trace out two parabolas whose common focus is the 
origin, and common latus rectum is equal to the diameter of 
curvature of the grating, the parabola for reflected light being 
convex to the source of light, and that for transmitted light 
concaye.—On some thermodynamical relations, part iv., by Prof. 
W. Ramsay and Dr. Sydney Young. The first part of this 
communication deals with Profs. Ayrton and Perry’s criticisms 
upon the previous papers by the authors upon this subject. In 
the second part a brief review is given of the various attempts 
that have been made to represent the pressure of a saturated 
vapour as a function of the temperature. 
Anthropological Institute, May 11.—Mr. Francis Galton, 
F.R.S., President, in the chair.—-Mr. Galton read some notes 
on permanent colour-types in mosaic, in which he advocated the 
adoption of certain specimens of mosaic material as permanent 
specimens of standard colours for the description of tints of 
skin. The original paintings by Broca, as well as the litho- 
graphs from them, have already changed colour, and some more 
permanent standard is greatly needed. There can be no ques- 
tion as to the persistence of the colours of mosaic: some speci- 
mens in St. Peter’s at Rome, that are more than a century old, 
have the appearance of being brand-new. The material is 
inexpensive, and as the variety of tints in the Vatican manufac- 
tory is very large, the flesh-tints appropriate to European nations — 
alone being about 500 in number, there would be no difficulty | 
in selecting such a series as anthropologists desire. —Prof. Flower | 
exhibited a Nicobarese skull, sent over by Mr. E. H. Man, 
together with some photographs of the natives.—Prof. Thane | 
read a paper by Prof. A. Macalister on some African skulls | 
and on a New Ireland skull in the Anatomical Museum of the 
University of Cambridge.—Dr. Garson reported that the corre- 
spondence as to an international agreement on the cephalic | 
index had been brought to a satisfactory conclusion, and that the - 
scheme advocated by him in his paper read before the Institute 
in February last had been accepted by sixty of the leading 
anthropologists on the Continent.—Dr. Garson read a paper on 
the skeleton and cephalic index of Japanese. qi 
Entomological Society, May 5.—Prof. J. O. Westwood, 
M.A., in the chair.—The following were elected Fellows :—The | 
Rey. E. N. Bloomfield, M.A., Mr. F. Fitch, Mr. A. J. Rose, 
and Mr. W. E. -Nicholson.—Mr. J. Jenner-Weir exhibited a 
large spiny Lepidopterous larva from Western Africa.—Mr. 
Stevens exhibited 4/fzon sorbi and other Coleoptera recently ob- 
tained in the Isle of Wight.—Mr. Crowley exhibited four speci- 
mens of Zefo venus, a large moth belonging to the family 
Hepialide, from Natal.—Mr. Howard Vaughan exhibited a long | 
series of Cidaria immanata from Kent, Surrey, Perthshire, Isle’ 
of Man, Isle of Arran, the Orkneys and Shetlands. He also 
exhibited C. vzssata from various localities in the south of Eng- 
land, and from Perthshire, Argyllshire, and the Islands of Arran, 
Lewis, and Hoy. Mr. Vaughan further exhibited varieties of C. 
suffumata from Dover and Darlington. Prof. Westwood com- 
mented on the interesting nature of the exhibition of C. zmanata, 
and stated that he had never before seen such a wonderful col 
lection of varieties of 2 single species.—The Rev. W. W. 
Fowler exhibited Staphylinus latebrico’a and Quedius truncicola, 
both from the New Forest.—The Secretary exhibited, for M. H, 
de la Cuisine, of Dijon, coloured drawings, life-size, of a variety | 
of Urania crasus and a variety of Papilio memnon.—Mr. G. 
Elisha exhibited specimens of Avtispila pfeifferella, together 
with the cases, and the leaves mined by the larvae.—Mr. J. W. 
Slater read a paper ‘‘ On the Origin of Colours in Insects,” in 
which he showed that the assertions of Mr. Grant Allen, that all 
brightly-coloured insects were flower-haunting species were in- 
correct, and that many brilliantly-coloured insects were carni- 
vorous. Mr. McLachlan said that the physiological question in. 
connection with colour had not been paid attention to ; he! 
thought that colour in insects was, to a great extent, ere Y 
upon the circulation of fluids in their wings. The discussion 
was continued by Prof. Westwood, Mr. H. Goss, the Rev. Ww. 
W. Fowler, Mr. Jacoby, and Mr. Weir. 1 
Victoria (Philosophical) Institute, May 3.—A paper by 
M. Maspero, describing his discovery of many Syrian geo- 
graphical names in the lists of Thothmes III., was read. It was| 
illustrated by a map, specially prepared by the author, as an aid, 
to the inquirer in following his description of the Egyptian 
account of the events connected with each name. M. Maspero 
concluded his statements in the following words :—‘‘ Such are 
the observations which a long study of the lists has suggested to 
me. Ihave elsewhere given the justification of my transcrip- 
tions. I have endeavoured to bring to my identificaticns the 
same prudence that I have exercised in my transcriptions. The 
The names enumerated arrange themselves almost wholly in the’ 
districts that surround Megiddo ; Qodshu, Damascus, and two) 
or three other towns at most belong to countries compara- 
tively remote. This result, to which the independent study o 
the lists has led me, arises clearly from the history of the cam- 
paign as the inscription at Karnak makes it known to us. In the 
year 23 (of his reign) Thothmes III.-set out from Gaza, cleared] 
Carmel, beat the confederates, including the prince of Qodshu, 
under the walls of Megiddo, besieged and took the town, ther 
returned to Egypt without pushing farther on towards the north. 
The fall of Megiddo was decisive, for, as Thothmes ITI. ha 
himself observed, ‘every chief of the whole country [was shu 
up] in it, so that the capture of Megiddo was as good as the 
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