308 
C. Vincent. The results of the author’s researches are : (1) The 
separation of the three normal propylamines ; (2) the discovery 
of nitrosodipropylamine ; (3) the determination of the physical 
constants of di- and tripropylamine and of nitrosodipropylamine. 
—On a new creatinine (ethylamido-acetocyamidine), and on the 
formation of the creatinines and creatines, by M. E. Duvillier. 
From the author’s experiments it follows, so far, that the action 
of cyanimide on the starch acids consists essentially in the forma- 
tion of creatinines, that of creatines taking place only in a very 
few cases.—On a combination of stannic chloride with hydro- 
chloric acid (chlorostannic acid), by M. R. Engel. —On the alco- 
holate of potassa, by M. E. J. Maumené. Referring to M. 
Engel’s note in the last issue of the Comptes Rendus, the author 
points out that he had already determined and announced an 
alcoholate of potassa so far back as the year 1872 (Les Mondes, 
December 19, 1872).—Note on the antennz of the Eunicians, 
by M. Et. Jourdan.—On the effects of pollinisation in the orchid 
family, by M. Léon Guignard. A series of experiments is 
described which the author has carried out for the purpose of 
determining the varying interval which intervenes between 
pollinisation and fertilisation in this group of plants.—On the 
amphibolic schists and gneiss, and on the limestones of Southern 
Andalusia, by MM. Ch, Barrois and Alb. Offret.—Fresh ex- 
periments with balloon photography: ascent of MM. A. and 
G. Tissandier and P. Nadar, by M. G. Tissandier. During 
this ascent, which took place on July 2, and lasted nearly six 
hours, the altitude never exceeding 1700 metres, M. Nadar took 
no less than thirty instantaneous photographs ; of these about a 
dozen constitute undoubtedly the finest series of negatives yet 
obtained from a balloon. Amongst them were two views of 
Versailles at 800 metres ; one of Sévres at 600 metres ; one of 
Balleme (Orme) at 900 metres ; several perspectives of Saint- 
Remy (Sarthe), some at 1200 metres. During a second ascent 
the following week, M. Nadar secured three good views of 
Champigny and the banks of the Marne. These experiments 
place beyond all doubt the success of aérial photographic 
operations. 
BERLIN 
Physical Society, June 4.—Dr. Pringsheim spoke on anew 
application of the telephone for the measurement of electrical 
resistances, a purpose for which it had already been brought into 
use by Prof. Kohlrausch in cases in which the resistances were 
measured by means of alternating currents—in cases, that is, of 
fluid conductors and also in the case of wires. Dr. Pringsheim had, 
however, observed that in the measurement of wire-resistances by 
means of alternating currents the determinations by the telephone 
did not always concur with those of the galvanometer, and 
varied very much with repeated measurements. He therefore 
applied the telephone for measurement by means of a constant 
current, and that in the following manner. In the Wheatstone 
bridge the circuit usually occupied by the galvanometer was 
of constant resistance. he four sides of the wire arrange- 
ment contained the wire the resistance of which required to be 
measured, and the rheostat. The two free angles of the square 
were connected by a wire circuit in which was placed a telephone. 
So long as the resistances of the two sides of the bridge were 
not perfectly equal, a part of the current flowed through the 
telephone circuit, and each time this was opened a snapping was 
heard in the telephone. The rheostat resistance was then 
changed till nothing was heard on opening the telephone circuit. 
The sensitiveness of this method was equal to 0'04 per cent. of the 
total resistance. —Prof. von Helmholtz reported on his most recent 
investigations, which respected the ‘‘ doctrine of the maximum 
economy of action,” and communicated the interesting history of 
the understanding of this principle. The doctrine was first pro- 
pounded by Maupertuis in 1744 ina treatise laid before the Paris 
Academy. This treatise contained, however, no general statement 
of the proposition, nor did it define the limits of its applica- 
bility, but only adduced an example. This example was, in 
accordance with the present state of our knowledge, not 
pertinent, and had no relation to the principle of the actio minima. 
Two years later Maupertuis propounded his principle before 
the Berlin Academy, proclaimed it to be a universal law of nature 
and the first scientific proof of the existence of God. On this 
occasion, too, he did not prove the proposition nor determine 
the limits of its applicability, but only supported it by two 
examples, one of which alone was correct. This principle, 
propounded with such grand solemnity, but so weakly sup- 
ported, was violently attacked by Konig of Leipzig, and just as 
NATURE 
[Fuly 29, 1886 
keenly defended by Euler. This mathematician likewise failed 
to furnish the proof, which was not possible till after the investi- 
gations of Lagrange. The form in which the principle of the 
actio minima now existed was given to it by Hamilton, and the 
Hamiltonian principle for ponderable bodies was in complete 
harmony with the Lagrange propositions. The elder Neumann, 
Clausius, Maxwell, and the speaker had already extended the 
Hamiltonian principle to electro-dynamics. For this purpose, 
and in order to be able to subordinate to it all reversible pro- 
cesses, the speaker had undertaken some transformations of it, 
and had introduced into it the conception of the ‘‘ kinetic 
potential.” Inthe form it had thus attained the Hamiltonian law 
—the old principle of the actio minima—had in point of fact 
universal validity, It had just as wide an application as had the 
law of the conservation of energy, and revealed a whole series 
of mutual relations between the different physical processes. In 
his communication Prof. von Helmholtz gave only a quite general 
view of his investigations. 
BOOKS AND PAMPHLETS RECEIVED 
“Studies from the Biological Laboratories of the Owens College,’’ vol. i. 
(J. E. Cornish, Manchester).—‘‘ Exterior Ballistics,” by J. M. Ingolls (Van 
Nostrand). —“ Essays relating to Indo-China,” 2 vols. (Triibner).—‘‘ Fifth 
Annual Report of the United States Geological Survey,’ by J. W. Powell 
(Washington).—** The Chemistry of Wheat Flour and Bread,’’ by W. Jago 
(Brighton).—‘‘ Annual Report of the University College and Free Library 
Committee of the Borough of Nottingham,” 1885-86.—‘‘ Report on the Pro- 
gress and Condition of the Botanic Garden and Government Plantations of 
South Australia, 1885,’” by R Schomburgk (E. Spiller, Adelaide) —“* Long- 
man’s School Geography,’’ by G. G. Chisholm (Longmans).—‘‘ Annuaine 
Geologique Universel et Guide du Geologique, 1886,” vol. ii., by Dr. Dagin- 
court.—‘‘ Proceedings of the American Association held at Philadelphia,” 
2 parts (Salem).—"* fhe Law of Storms,’’ second edition, by W. H. Rosser 
(Norie and Wilson).—*‘ Fourth Report of the U.S. Entomological Commis- 
sion” (Cotton Worm and Boll Worm), by H. Riley (Washington).—'* Pro- 
gress of Astronomy, 1885,” by W. C. Winlock (Washington).—“ Bulletin de 
la Société Impériale des Naturalistes de Moscou,” Nos. 3 and 4 (Moscou). 
—‘‘ Original Mittheilungen aus der Ethnologischen Abtheilung der Kénig- 
lichen Mus. zu Berlin,” Erster Jahrgang, Heft 1, 2, 3 (Spzrmann, Berlin). 
CONTENTS PAGE | 
Electric Transmission of Energy. By Prof. John 
Perry, /PoRsS ce: oo cu ces neni ol oh cyto ae 
Our Book Shelf :— 
Tregear's “Aryan Maori” . ... . .. « « = ») 9280 
Letters to the Editor :— 
Tidal Friction and the Evolution of a Satellite.— 
James Nolan; Prof. G. H. Darwin, F,R.S.. 286 
Peripatus in Demerara.—John J. Quelch .... 288 
Upper, Wind-Currents over the Bay of Bengal in 
March, and Malaysia in April and May.—Hon, 
Ralph Abercromby =. 5 5. <= = - -sameeod 
Mock Sun:—Sir W. J. Herschel... | |S suena 
‘The Duration of Germ-Life in Water.”—Percy 
Fe Frankland!) 05 cece se stn ete ne 
Animal Intelligence.—Hy. Ling Roth ... . 289 
The Microscope as a Refractor.—L. Bleekrode. . 290 
Herrmann’ Abich 6) 5 2 () ©) cite testes ne elie oe 
Capillary Attraction, II, By Sir William Thomson, 
F:RiS. ((Ziustrated) 58 se fe © 1 tat ecto ECO 
The Science and Art Department Examination in 
Ghemistry~ fie wc. ce =) tet = cel oleee ae eee 
Notes: 6.8 204550e, Ge etnstos oue ciwiaige Rebrouopree 
Astronomical Phenomena for the Week 1886 
August 1-7 «oes 2 ee witeyio: esi) lose) ee 
The Volcanic Eruption in New Zealand .. . 301 
Science in New South Wales .......... 303 
Ice Movementsin Hudson’s Bay. By Lieut. A. R. 
Gordon; (RAINS 02) 100% alton fees eect (er-tn-? Tom Co 
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Societies and Academies ..........+. + 305 
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