July i. 1920] 



NATURE 



571 



The regularity of cutting is unaffected by wear. The 

 rigid connection between hand and object and the 

 smallness of the friction and inertia of the moving 

 parts make for convenience of manipulation. The 

 knife-holder is easily adjusted to give a slicing cut, 

 and can also be moved so that sections can be cut 

 with new parts of the knife as it becomes blunt or 

 damaged. A simple accessory also enables the clear- 

 ance angle of the knife to be adjusted. 



Paris. 

 Academy of Sciences, June 14.— M. Henri Deslandres 

 in the chair. — The president announced the death of 

 Prof. Auguste Righi, and gave a short account of his 

 life-work. — A. Rateau : Maps of the network of elec- 

 tricity distribution in France. Work of the Technical 

 Committee of the Hydrotechnical Society of France. 

 An account of the work of the sociefy since its estab- 

 lishment in 1912. Its object is the study of all ques- 

 tions relating to the regulation and utilisation of 

 waterfalls. The map, on the scale of 1/200,000, will 

 consist of eighty-four sheets, seventy-eight of which 

 are now submitted to the Academy.^C. Guichard : 

 Determination of the congruences C and the con- 

 gruences 20 which belong to a linear complex. — 

 Ch. Ed. Guillaume : The action of metallurgical addi- 

 tions on the anomaly of expansion of the nickel-steels. 

 I Certain applications of nickel-steels render necessary 

 I the addition of other elements — manganese, carbon, 

 chromium, tungsten, and vanadium. A detailed study 

 j of the action of additions of manganese, chromium, 

 I and carbon has been made, and the results obtained 

 have been summarised in two diagrams. — J. Tilho : 

 The frequency of fogs in the Eastern Sahara. Detailed 

 observations of these dry dust fogs are necessary, 

 especially in the interest of aerial navigation. The 

 results of three years' observations are given, classified 

 as thick, medium, and light, according to the month. 

 The fogs are relatively rare in the months be- 

 tween August and November. — M. Ch. Riquier was 

 elected a correspondant for the section of geometry 

 in "succession to the late M. Zeuthen, and M. Pierre 

 Weiss correspondant for the section of general physics 

 in succession to Sir J. J. Thomson, elected foreign 

 associate. — E. Cartan : The projective deformation of 

 surfaces.- — ^J. Andrade : The special right lines of con- 

 tact of general helices. — S. Procopiu : The double 

 refraction and dichroism of the fumes of ammonium 

 chloride in the electric field. The double refraction 

 and dichroism of ammonium chloride fumes vary with 

 the time and differently. The double refraction varies 

 very nearly inversely as the square of the wave-length, 

 and the dichroism inversely as the third power. If 

 the phenomenon predicted bv Voigt exists, it is 

 masked.— MM. La Rosa and A. Sellerio : A galvano- 

 magnetic effect parallel to the lines of force and 

 normal to the current. — G. Le Bon : Certain 

 antagonistic properties of various regions of the 

 spectrum^ A screen of zinc sulphide placed behind a 

 trough containing" a solution of sulphate of quinine 

 remains unaffected; if a trough of ammoniacal copper 

 sulphate solution is superimposed, the zinc sulphide 

 screen phosphoresces. Similar phenomena were 

 utilised for signalling at night during the war. — J. 

 Mennier : The catalytic action of aluminium in the 

 preparation of the chlorobenzenes. .Aluminium is 

 superior to the usual catalyst, iodine, in this prepara- 

 tion. A weight of aluminium equal to one-thousandth 

 of the benzene gives the best results, h detailed 

 example of the method is given. — P. Landrieu : Re- 

 searches on the polyacid salts of the monobasic acids : 

 sodium tribenzoate. — R. Blanchard : The Durance 

 fiflacier at Sisteron. — L. Cayeux : The iron minerals 

 of the Longwy-Briey basin.— G. Mangenot : The 

 NO. 2644, VOL. 105] 



chondrionie of the Vaucheria. Further experimental 

 evidence, both on the living plant and on fixed stained 

 sections, in support of the views put forward in an 

 earlier communication and adversely criticised by M. 

 Dangeard. — E. Saillard : The sugar-beet during the 

 war. The general conclusion is drawn that by using 

 little manure, and especially little nitrogenous 

 manures, the roots are richer in sugar and easier to 

 work. The total production of sugar per hectare is 

 alone affected by this abnormal culture. Similar 

 results have been obtained in Germany.— Ch. Porcher : 

 Want of food and the chemical composition of milk. 

 A criticism of the experiments of Lamj, together 

 with additional work on the same subject. While 

 accepting the figures of Lami, the author gives them 

 another interpretation, and considers that the varia- 

 tions of chemical composition observed are due to 

 the retention of milk and not to starvation. — P. 

 Mathias : The structure of the lips of fishes of the 

 genus Chondrostoma (family Cyprinidae).— M. 

 Piettre and A. Vila : The separation of the proteins 

 of the serum. The technique proposed differs con- 

 siderably from the classical methods studied by Hof- 

 meister, Starke, Michailoff, and J. Kauder, as large 

 quantities of mineral salts are not used. The serum 

 is exactly neutralised, precipitated by acetone, and the 

 albuminoids extracted with water, the last washings 

 being saturated with carbon dioxide. The insoluble 

 proteins free from albumin are left as a greyish-white 

 precipitate. — G. Bertrand and Mme. Rosenblatt : The 

 action of chloropicrin upon some bacterial fermenta- 

 tions. Details of experiments on the action of chloro- 

 picrin at different concentrations on the lactic fer- 

 ment, the ammoniacal ferment, and the sorbose bac- 

 terium. Chloropicrin was found to exert a strongly 

 toxic action upon all living cells, and is comparable, 

 in some cases, with the most powerful known dis- 

 infectants. — A. Frouin : Variations in the fatty matters 

 of the tubercle bacillus cultivated on definite media in 

 the presence of earths of the cerium group.- — F. 

 Ladreyt : Trophic superactivity : giant cell and cancer. 

 — MM. Faur^-Fremiet. Guieysse, Magne, and A. Mayer : 

 Cutaneous lesions determined bv certain vesicant 

 compounds. 



Books Received. 



Chemical Theory and Calculations. By Prof. F. J. 

 Wilson and Prof. I. M. Heilbron. Second edition. 

 Pp. vii+144. (London: Constable and Co., Ltd.) 

 4s. 6d. net. 



The Elements of Electro-Technics. By A. P. 

 Young. Pp. viii+348. (London : Sir Isaac Pitman 

 and Sons, Ltd.) 7s. 6J. net. 



Historical Geography of Britain and the British 

 Empire. In two books. Book i. : The Making of 

 England : The Making of Empire : The Establish- 

 ment of Empire, B.C. 55 to a.d. 1815. By T. Franklin. 

 Pp. viii-f2i6. (Edinburgh: W. and A. K. Johnston, 

 Ltd.; London :. Macmillan and Co., Ltd.) 2.v. net. 



Space, Time,' and Deity. By Prof. S. Alexander. 

 2 vols. Vol. i., pp. xvi+347 ; vol. ii., pp. xiii + 437. 

 (London : Macmillan and Co.. Ltd.) 366'. net. 



Education for Self-Realisation and Social Service. 

 Bv F. Watts. Pp. xii+275. (London : University of 

 London Press, Ltd.) 75. 6d. net. 



The Child Welfare Movement. By Dr. Janet E. 

 Lane-Clavpon. Pp. xi + 341. (London: G. Bell and 

 Sons, Ltd.) 75. net. 



K Summer Tour (1QI9) throusfh the Textile Districts 

 of Canada and the United States. By Prof. A. F. 

 Barker. Pp. xi+197. (Leeds: Printed by Jowett 

 and Sowry, Ltd.). 



