August i8, 1892] 



NATURE 



387 



study would be that of the Administration of Forests. The 

 forest inspectors and their agents are called upon by their 

 functions to travel over the high valleys of the Alps ; they would 

 thus be able, without great additional labour, to undertake the 

 observation of glaciers. 



As to the programme on which they should work, we would 

 simplify it as much as possible, and reduce it to two points : — 



1. To attentively survey the glaciers in order to fix for each 

 one the year of maximum and the year of minimum extent in 

 their successive variations. 



2. To specially watch the dangerous glaciers, and warn the 

 Administration of the danger they may cause by assuming ex- 

 aggerated dimensions during their phase of development. 



In order to carry out this double programme, the Government 

 should charge each inspector of forests to study the glaciers of 

 his district, and to inscribe on a register ad hoc the state of 

 growth and decline of each glacier every year. For important 

 glaciers, interesting or dangerous, he should have measurements 

 made from fixed marks, and state in exact figures the changes in 

 the dimensions of the glaciers ; for little, uninteresting, or un- 

 important glaciers, occasional inspection and the reports of the 

 mountaineers would suffice to ascertain their state of growth or 

 decrease. 



M. Antoine de Torrent, Inspector-General of the Forests of 

 Le Valais, has long been occupied in collecting observations on 

 the glacial variations of our Alps ; it is from him that we have 

 obtained all the facts recorded by science in this field of research 

 in Le Valais ; it is for him, not for us, to give instructions as to 

 the way in which the observations should be organized. 



This study is not an expensive one ; it calls for no great out- 

 lay on the part of the State, nor does it make great demands on 

 the powers and the time of the observers. It may lead to im- 

 portant and useful results. It can only be successfully carried 

 out by the State, since that alone has the necessary persistence 

 to continue it long enough. I therefore venture to recommend 

 these studies on the variation of glaciers to your great benevo- 

 lence, and to the enlightened solicitude with which you follow 

 all questions interesting to the public welfare. Men of science, 

 who consecrate their lives to the study of the phenomena of 

 nature, are ready to help you to the best of their ability to study 

 these questions from a theoretic point of view. But it is neces- 

 sary, in order to arrive at practical results, to have a collection 

 of materials of observation which the State alone seems to us 

 capable of bringing together with success. 



Accept, M. le Conseilleur de Etat, the expression of my very 

 respectful and devoted consideration. 



F, A. FOREL. 



Morges, February lo, 1892. 



SOCIETIES AND ACADEMIES. 



Paris. 

 Academy of Sciences, August 8. — M. de Lacaze-Duthiers 

 in the chair. — The '* Pythonomorphs of France,' by M. Albert 

 Gaudry. Announcing the discovery of the snout of one of the 

 great chalk reptiles termed pythonomorphs by M. Cope, on 

 account of their similarity to the sea serpent as imagined by the 

 ancients. The specimen is from a pythonomorph lOm. long, 

 and was found in the upper chalk of Cardesse, near Pau, It is 

 similar to the Mosasaurtis giganteus of Maestricht, and has been 

 termed Liodon mosasajiroides. A smaller and somewhat similar 

 specimen was also found, and was termed Liodon compressidens. 

 These and a few minor fragments are the first representa- 

 tives of the pythonomorphs found in France. — On the 

 production of sugar in the blood at the expense 

 of the peptones, by M. R. Lepine. — On the lava of July 12, 

 1892, in the torrents of Bionnasay and Bon-Nanl (catastrophe 

 of Saint-Gervais, Haute Savoie), by M. P. Demontzey. After 

 describing the probable course of the catastrophe, the writer 

 comes to the following general conclusion : — That the lava of 

 July 12 has behaved exactly like those which have been observed 

 before in the torrents of the Alps and the Pyrenees. That its 

 energy was all the more disastrous as the transport in masses 

 commenced in the most elevated regions of the torrent basin 

 after the sudden bursting forth of a large body of water concen- 

 trated more rapidly even than in the most violent hailstorms in 

 the upper basins of torrents without glaciers. That the volume 

 of the deposited materials of all sorts — estinr.ated at about one 

 million cubic metres— presents no anomaly in c ^mparison with the 



NO. 1 1 90, VOL. 46] 



relatively small amount of water, which effected the transport 

 by a series of successive bounds, with alternate momentary 

 accelerations and retardations of speed. That this torrent 

 phenomenon has substituted for a simple and hitherto harmless 

 rivulet a torrent whose activity can be mastered with a relatively 

 short delay. That both in the Alps and the Pyrenees similar 

 cases of the transformation of peaceful rivulets into formidable 

 torrents can be cited, aggravated by the fact of their being 

 caused by rain, which is even more difficult to predict and ward 

 off than the dangers presented by a glacier. And lastly, that 

 this great disaster could not have been provided against, since 

 nobody had had the idea even of exploring the glacier of 

 Tete-Kousse. — On a property of lamellar bimetallic con- 

 ductors submitted to electromagnetic induction, by MM. 

 Ch. Reignier and Gabriel Parrot. An arrangement re- 

 calling Faraday's disc is obtained by substituting for the 

 ordinary copper conductors thin plates composed, along their 

 thickness, of a very magnetic and a highly conducting metal, 

 so placed that the lines of force are perpendicular to their 

 thickness. The flow of induction emanating from the north 

 pole is divided into several sheets of parallel lines very close to- 

 gether, which only traverse the magnetic portions of the bime- 

 tallic conductors, and the tubes of force become cylindrical. 

 The available energy in such an arrangement increases at a rate 

 which is sensibly proportioned to the height of the conductors. 

 An apparatus constructed on this principle gave, with a weight 

 of 750 kg. and a velocity of 500 revolutions, 32,000 watts 

 giving an output of 42 watts per kg. of the machine. — The 

 application of the measurement of density to the determination 

 of the atomic weight of oxygen, by M. A. Leduc. The com- 

 position of water by volume, and thence its composition by 

 weight, were determined by finding the density of a mixture of 

 hydrogen and oxygen produced by the electrolysis of an alkaline 

 solution. After an electrolysis of several days, during which 

 the superfluous gas was allowed to escape through mercury, the 

 liquid and the platinum poles were saturated with gas, and the 

 density obtained by the method previously described did not 

 vary by more than o •0001 gr. The value within xh» per cent, was 

 0*41423. The volume ratio between hydrogen and oxygen was 

 2*0037 at o% and the atomic volume of oxygen 1*9963. The 

 atomic weight of oxygen by this method is 15 "877, and by the 

 synthetic method 15*882, so that 15*88 must be taken for the 

 mean atomic weight. Hence the molecular weight of water 

 vapour is 17*88, and its theoretical density 0*622. — On the 

 general form of boiling-point curves for central substitution 

 compounds, by M. G. Hinrichs. — Note on the existence in the 

 earth of an acid mineral substance as yet undetermined, by M. 

 Paul de Mondesir. If all the carbonic acid contained in lime be 

 driven off by a strong acid, and the ratio of lime to carbonic acid 

 be carefully measured, the lime is found to exceed the quantity 

 necessary for saturation. The earth remains always acid and 

 capable of decomposing carbonate of lime in the cold. That this 

 acid residuum cannot be humic acid or free silica is proved by 

 the total destruction of the organic substances by ignition or 

 potassium permanganate, which leaves the property in question 

 unaffected. The quantity of acid matter varies froni "2 to I 

 per cent, of the earth. It is very stable, and its composition has 

 not yet been determined. — Calcareous soap and boiler explosions, 

 by M. A. Vivien. — Pupine, a new animal substance, by M. A. 

 B. Griffiths. This is extracted from the skin of the chrysalis of 

 several lepidoptera.— On the colouring matter oi Micrococcus 

 prodigiostis, by the same. — On the coccoid state of a nostoc, by 

 M. C. Sauvageau.— On an alga living in the roots of the Cycadea, 

 by M. P. Hariot. — On the presence of fossils in the azoic for- 

 mations of Bretagne, by M. Charles Barrois.— On the discovery 

 of cut flints in the quaternary Rhinoceros Mercki alluvium of the 

 Saone valley at Villefranche, by M. Ch. Deperet. 



Rome. 

 R. Accademia dei Lincei, June 5. —The 289th annual 

 meeting, honoured by the presence of H. M. King Umberto I. 

 —The President introduced the two committees charged with 

 the examination of the works in competition for the two royal 

 prizes of 10,000 lire each, one for social and economic sciences, 

 the other for mathematical sciences. Senator Lampertico, re- 

 porting for the first committee, said that, although two essays, 

 one on " Ancient Socialism," by Salvatore Cognetti de Martiis, 

 and another on the laws of the distribution of wealth, bearing 

 the motto, " Laboremus," had shown considerable merit, the 

 committee had not felt justified in awarding the prize to either. 



