May 25, 1899] 
NATURE 
95 
Acanthomysis having been defined in such a manner as to 
exclude the type. Reasons are given for doubting the specific 
validity of MWacromysts neglecta, G.O.S., and the characters of 
Erythrops serrata, G.O.S., are re-defined.—Prof. J. Joly, 
F.R.S., communicated a paper, by Mr. Kingsley D. Doyle, on 
the Rio del Fuerte of Western Mexico and its tributaries. The 
paper is a valuable series of notes, arranged topographically, 
concerning the geology, physical geography, and meteorology 
of the district explored. 
EDINBURGH. 
Royal Society, May 1.—Prof. Copeland in the chair.— 
Lord Kelvin’s paper on the application of force within a limited 
space required to produce spherical solitary waves, or trains of 
waves, of both or either species, equivoluminal and irrotational, 
in an elastic solid, was briefly described. It will be found in 
the May number of the PAz/osophical Magazine.— Dr. Alexander 
Galt, in a further communication on the heat of combination of 
pairs of solid metals, mentioned that practically there was no 
heat of combination in copper-silver alloys, but that heat of 
combination was found in most of the copper-zine alloys. The 
maximum was obtained when the metals, considered as bivalent 
elements, were in proportions approximating to their chemical 
combining proportions—about 49°8 per cent. copper. With 
diminishing percentage of copper, the heat of combination 
gradually diminished, becoming zero when there was about 30 
per cent. of copper. With still smaller proportion of copper, 
the heat of combination became negative.—Dr. C. Wace 
Carlier read a paper on changes that occur in some 
cells of the newt’s stomach during digestion. As soon as 
food is swallowed, secretion commences near the cesophagus 
and sweeps in a slow wave along the whole organ, 
reaching the pyloric glands in one to two hours. Each 
cell is exhausted in about four hours, following which 
there is a period of rest and recuperation lasting other 
four hours. During exhaustion, the nuclei undergo changes in 
size, losing chromatin, which is used up in the production of 
prozymogen. The nucleoli are effete products, derived mainly 
from the chromatin, and are extruded from the nuclei. The 
prozymogen passes into the cytoplasm and unites with an 
albuminous material to form zymogen, which is readily con- 
verted into zymin by the action of weak acids. Repair of 
chromatin begins by the passage into it of substances from the 
cytoplasm. These become gradually broken up, the nuclear 
radicle passing to the chromatin, and the albuminous material 
to the nucleoli as effete matter. When (but not until) this 
process is complete, the cell is again ready to recommence 
secretion if called upon to do so. Oxyutic cells divide by 
mytosis, and, in process of division, secrete zymin and form 
prozymogen from the chromatin just as cells not in process of 
division do.—In a paper on the leakage of electricity from 
charged bodies at moderate temperatures, Prof. J. C. Beattie 
described in detail results of experiments with zinc and iron 
plates coated with various substances. Under any given con- 
dition the rate of leakage of charge from the insulated plate 
was determined (1) at ordinary temperatures ; (2) at temper- 
atures of 150°-300° C. With the plate by itself or covered by 
certain materials there was no change in the rate of leakage as 
the temperature was raised. With certain coatings, however, 
there was greatly increased leakage at the higher temperatures. 
This was the case, for example, when zinc was coated with 
potassium bichromate and iodine; and when iron was coated 
with potassium permanganate or with potassium acetate.— 
Professor Tait, in a note on the linear and vector function, 
showed that if represented a strain with three real roots, so 
also cid J ¢ WY + where w was any linear and vector function 
whatever. As formerly shown, » may be written as the 
product, » 7, of two pure strains. Hence y oy t=yYov’. 
Y'ry~', in which each triple compound is obviously self- 
conjugate, and hence y @ ~~! can also be expressed as the product 
of two pure strains. 
Paris. 
Academy of Sciences, May 15.—M. van Tieghem in the 
chair.—M, Pnillieux took his place as a member of the 
Botanical Section. — Experimental application of decimal 
circular divisions in practical navigation, by M. E. Guyou. 
An account of some experiments to be undertaken on the ex- 
tension of the decimal system to the instruments and tables 
employed in navigation. The advantages of the system and 
NO. 1543, VOL. 60] 
the difficulties attending its introduction are discussed.—Fffects 
of auto-excitation of the heart by the extra-current of the 
electromagnetic indicator used in recording cardiac valvular 
movements, by M. A. Chauveau. Further experiments are 
described, showing the extreme sensitiveness to induced currents 
of the heart of the horse.—New elements of the orbit of the 
planet EL, by MM. Lubrano and Maitre.—Representation of 
uniform branches of analytic functions, by M. G. Mittag-Leffler 
—Calculation of formulze containing arbitrary functions, by M. 
Jules Beudon.—Want of generality in the theory of the 
fictitious polarisation of dielectrics, by M. H. Pellat. The 
theory in question is incapable of explaining the forces pro- 
duced when a dielectric, originally non-electrified, is placed in 
an electric field.—Influence of the source of electricity in the 
use of Michelson’s vacuum tubes, by MM. A. Perot and Ch. 
Fabry. The best results, as regards the production of pheno- 
mena of interference, are obtained by the use of a continuous 
current with an electromotive force of at least 700 or 800 volts. 
—On the electrolytic luminous sheath, by M. E. Lagrange. — 
Substitution of magnetic for mechanical action in coherers, by 
M. Th. Tommasina. The chains formed by the metallic 
particles are broken by the action of an electromagnet.— 
Transmissior of light through turbid media, by M. P. Compan. 
It is shown experimentally that the nature of the light trans- 
mitted by turbid media is dependent on the dimensions of 
the suspended particles.—Calculation of the compressibility of 
a gaseous mixture from the compressibility of its com- 
ponents, by M. Daniel Berthelot. The method of calculation is 
based on Van der Waals’ formula, and the theoretical numbers 
show a satisfactory agreement with the experimental values. — 
On the preparation and properties of tungsten pentabromide, 
by M. Ed. Defacqz. A new method for the preparation of 
tungsten pentabromide is described, based on the action of 
dry hydrogen bromide on the hexachloride at about 300°C. The 
satisfactory yield obtained by this process enabled the properties 
of the compound to be studied more completely than has hitherto 
been possible.—On the mixed halogen salts of lead, by M. V. 
Thomas. The author describes a bromochloride of the formula 
3PbCl,, PbBr,, obtained by mixing solutions of lead chloride 
and potassium bromide, a bromochloride PbBrCl formed by the 
action of bromine on the corresponding chloriodide which has 
previously been described, and a bromoiodide of the formula 
3PbBra, PbI,. A bromoiodide having the composition PbBrI 
also appears to exist.—Separation and estimation of traces of 
bromine in the presence of a large excess of chlorides, by M. H. 
Baubigny. The bromine is separated from the bulk of the 
chlorine by distilling the salts with potassium permanganate and 
a limited quantity of hydrochloric acid. Less than 00005 
gramme of bromine may thus be detected and estimated in the 
presence of 10 grammes of sodium chloride.—On the activity of 
manganese in relation to the phosphorescence of strontium 
sulphide, by M. José Rodriguez Mourelo. The influence of 
manganese carbonate, in rendering strontium sulphide phos- 
phorescent, is similar to that of bismuth subnitrate as described 
In previous communications.—On pectins, by M. Em. 
Bourquelot. Five varieties of pectin, obtained from different 
plants, have now been examined. All are dextrorotatory to a 
greater or less extent, and their solutions are coagulated by 
pectase. On hydrolysis with dilute sulphuric acid arabinose is 
obtained, whilst mucic acid is formed on oxidation with nitric 
acid.—Action of toluylene-diamine on the red corpuscles of the 
blood, by MM. L. Lapicque and A. Vast. Experiments tend 
to show that the toxic action of toluylene-diamine is due not so 
much to a specific destruction of the corpuscles as to an alteration 
of the latter which facilitates their destruction by the heematolytic 
organs, and especially by the liver.—On the galvanotropism of 
ciliated infusoria, by M. Henri Mouton. The phenomenon of 
galvanotropism appears to be due to the direct action of the 
current, and not to the chemiotropic action of the pro- 
ducts of electrolysis.—On the forms of conservation and re- 
production of ** black rot,” by M. Joseph Perraud. It follows, 
from the author’s observations, that burying the affected parts of 
the plant is of no avail unless the soil is subsequently left un- 
disturbed. —Botrytis cinerea and the ‘* Toile” disease, by M. J. 
Beauverie. The destructive action of the parasite is tavoured 
by a high temperature, a moderately nutritive substratum, and 
a confined atmosphere saturated with aqueous vapour.—On the 
germination of Veott2a nidus-avis, by M. Noel Bernard.—On 
a ¢achylzte from the bed of the North Atlantic Ocean, by M. P. 
Termier. 
