APRIL 29, 1915] 
NATURE 
251 

simple observations to prove certain problems dis- 
cussed in a previous paper on unsound Mendelian 
developments. The observations are :—(1) If one o 
more groups in a set of hybrids’ progeny carry a 
character outside those producing the set, that char- 
acter is common to all the groups in the set, For 
instance, if the characters carried by the four follow- 
ing groups have been found as set down, namely : 
agouti, 9 XY; cinnamon agouti, 3 Xy; black, 3xYZ; 
chocolate, 1xy; then the character Z is carried by 
the three remaining groups, for otherwise black would 
differ from agouti and chocolate in more than one 
pair of characters, and from cinnamon agouti in 
more than two. (2) A character carried by more 
than half the groups in a set of hybrids’ progeny is 
common to all the groups in the set. For instance, if 
the characters of three of the four groups in a set 
have been found as follows: agouti, 9 XYZ; dilute 
agouti, 3; black, 3xYZ; blue, 1xYz; then dilute 
agouti must also carry Y, and, by the symmetry of 
the set, the additional characters X and z.—Miss A. 
Wilson ; Changes in soils brought about by heating. 
The increased productivity of soil which has been 
subjected to different degrees of heat has been studied 
by E. J. Russell and F. J. Seaver and E. D. Clark. 
Russell suggests that the increased productivity is 
due to the increase in the number of nitrifying bac- 
teria consequent on the destruction of the larger 
organisms by heat. Seaver and Clark and others 
maintain that the heated soil owes its greater pro- 
ductivity to the increased amount of soluble matter 
due to the decomposition of soil constituents. In 
these experiments extracts of suitably prepared soil 
heated to various temperatures between 60° and 150° 
during periods of two hours were obtained. The 
depression of freezing point and the electrical con- 
ductivity of each solution were then determined. It 
was found that there was a marked range in the 
coloration of the solutions thus obtained, and each 
solution gave a marked reaction to litmus. sie 
amount of water retained by the heated soil was also 
noted in one set of experiments, and found to increase 
with the temperature to which the samples were 
heated. Throughout the experiments the depression 
of freezing point and electrical conductivity showed a 
marked increase in the solutions obtained from 
samples heated at the higher temperatures. 
Paris. 
Academy of Sciences, April 19.—M. Ed. Perrier in the 
chair.—A, Miintz and E. Lainé:; Studies on the agri- 
cultural value of the sediments carried by the water- 
courses of the Alps and Pyrenees. From the chemical 
point of view, these sediments have nearly the same 
proportions of fertilising materials as good average 
arable soils. They vary greatly in physical properties 
and measurements were made of the apparent density, 
porosity, capacity for water, and permeability of sedi- 
ments from different sources. The permeability varies 
greatly, and the fine sediments tend to choke the 
irrigated soil. Experience has shown agriculturists 
making use of irrigation the best means of dealing 
with this tendency to impermeability.—C. Guichard : 
A series of surfaces and the equations of Laplace 
which are reproduced by a transformation ‘(m, n) of 
Darboux.—V. Grignard and Ch. Courtot: Benzo- 
fulvanol and  benzofulvene. Starting with the 
magnesium compounds of cyclopentadiene, indene, 
and fluorene, and treating these with aldehydes and 
ketones, secondary and tertiary alcohols are obtained 
which have been named fulvanols, benzofulvanols, 
and dibenzofulvanols, and these, by dehydration, give 
the corresponding hydrocarbons. The preparation is 
described of the benzofulvanol obtained from indene 
magnesium bromide and trioxymethylene and_ the 
NO. 2374, VOL. 95| 

hydrocarbon benzofulvene obtained by its dehydration. 
—M. Riquier: Partial linear systems composed of 
equations equal in number to those of their unknown 
functions.—Rodolphe Sereau; Circular anamorphosis. 
—Pierre Humbert: The piriform figure of equilibrium 
of a fluid mass. Prof. Poincaré and Sir G. H. Darwin 
came to opposed conclusions as to the presence of 
points of inflexion on the section by a symmetrical 
plane of the equilibrium figure of a fluid mass in rota- 
tion. The author concludes that there are no points 
of inflexion and the calculations of Poincaré, pushed 
to the end, lead to the same result as those of Dar- 
win.—B. Globa Mikhailenko:; Modification of the 
ellipsoidal figures of equilibrium of a fluid mass in 
rotation under the action of capillary pressure.—M. 
Drzewiecki : Wind motors.—A. Leduc: The velocity of 
sound in gaseous mixtures. ©The application of a 
formula deduced in a previous communication to con- 
sideration of the velocity of sound in moist air, 
carbonic acid (Regnault’s experiments), and mixtures of 
air and methane. The deviations between experiment 
and the author’s theory are explained by the assump- 
tion that the latter is correct and that the gases used 
by Regnault and Capstick were impure.—Daniel 
Berthelot : The kinetics of photochemical reactions.— 
Ch. Courtot: The theory of the oscillation of the 
indene double linkage. The theory put forward by 
Thiele to explain his experimental results is unneces- 
sary, since owing to an isomeric change unperceived 
by him he was dealing with only one benzylindene, the 
y compound. The a-benzylindene has been prepared 
by the author, and is shown to be distinct.—M. and 
Mme. Fernand Moreau: Nuclear evolution and the 
phenomena of sexuality in the lichens of the genus 
Peltigera.—M. Fonzes-Diacon : Copper spraying fluids. 
The acid fluids have a high anticryptogamic action, 
the neutral and alkaline solutions are less active. 

BOOKS RECEIVED. 
Elementary Text-book of Economic Zoology and 

Entomology. By Prof. V. L. Kellogg and Prof. 
R. W. Doane. Pp. x+532. (New York: H. Holt 
and Co.) 1.50 dollars. 
The Fauna of British India, including Ceylon and 
Burma :—Mollusca (Freshwater Gastropoda and 
Pelecypoda). By H. B. Preston. Pp. xix+244. 
(London: Taylor and Francis.) tos. 
Electrical Instruments in Theory and Practice. By 
W. H. F. Murdoch and U. A. Oschwald. Pp. vili+ 
306. (London: Whittaker and Co.) Ios. 6d. net. 
The Development and Properties of Raw Cotton. 
By W. L. Balls. Pp. xii+221. (London: A. and C. 
Black.) 5s. net. 
Militarism versus Feminism. Pp. 64. (London: 
G. Allen and Unwin, Ltd.) 6d. net. 
Chemical Technology and Analysis of Oils, Fats, 
and Waxes. By Dr. J. Lewkowitsch. Edited by 
G. H. Warburton. Fifth edition, in 3 vols. Vol. iii. 
Pp. viiit+483. (London: Macmillan and Co., Ltd.) 
20s. net. i ; 
“Red Books’ of the British Fire Prevention Com- 
mittee. No. 196: Fire Tests with Glass. The Com- 
mittee’s Report. Pp. 20. No. 197: The Committee’s 
Report. Pp. 16. (London: British Fire Prevention 
Committee.) 2s. 6d. each. 
Heredity and Environment in the Development of 
Men. By Prof. E. G. Conklin. Pp. “xiv-+533- 
(Princeton: University Press; London: Oxford Uni- 
versity Press.) 8s. 6d. net. 
Histoire de 1l’Involution Naturelle. By Dr. H. 
Marconi. Pp. xiits505. (Paris: A. Maloine; 
Lugano: Maison d’Editions du ‘‘Coenobium.”) 15 
francs. 
