April 8, 1920] 



NATURE 



187 



when they were opposite, together with an equally 

 marked^ minimum frequency at the full when the 

 declinations were the same, and at the new when 

 they were opposite. At the quarters the frequency is 

 about average ; at the times of minimum the frequency 

 is about one-third, and at the maximum about five- 

 thirds, of the average. The magnitude, no less than 

 the fact that it is continuously recognisable through- 

 out the record, shows that the variation is a real one, 

 and it is difficult to find any other cause than the 

 effect of the stresses set up by the gravitational attrac- 

 tion of the sun and the moon. — A. F. Dulton : A new 

 apparatus for drawing conic curves. With the ap- 

 paratus described in this paper the conic is drawn as 

 the polar reciprocal of a circle. A four-bar linkage 

 constrains a pen to trace the locus of the pole of a 

 fixed straight line enveloping a circle upon paper 

 pinned to a rotating drawing-board. The instrument 

 draws, conies with precision. It traces the curves at 

 one sweep, and is applicable to all conies. — Capt. 

 J. W. Bispham : An experimental determination of the 

 distribution of the partial correlation coefficient in 

 samples of 30. The distributions are described of the 

 observed values of the partial and total correlations 

 from 1000 samples of 30 each. The three attributes of 

 the sampled (artificial) population are uncorrected, so 

 that observed values of the correlations are departures 

 from the true value, which is zero in each case. The 

 three groups of 1000 total correlations observed are 

 shown to be nearly Gaussian in form, and to be in 

 very close accord with the distributions predicted in 

 general form by R. A. Fisher, and evaluated in detail 

 in an important co-operative study described in 

 Biometrika. The distribution of partial correla- 

 tions is compared with the Gaussian, the Pearson 

 Type II., and the theoretical distribution of total 

 correlations referred to abov^. It is found to be 

 closelv fitted bv the latter, and not to show signi- 

 ficantly higher dispersion than is indicated bv the usual 

 expression for the s tand ard deviation of total correla- 

 tions, viz. i-p'/v'n-i. Some important practical 

 bearings of the result are indicated. 



Paris. 

 Academy of Sciences, March i.— M. Henri Deslandres 

 in the chair.— G. Humbert : The number of classes of 

 positive quadratic forms of Hermite, of given dis- 

 criminant, in an imaginary quadratic body. — Em. 

 Bourquelot and M. Bridel : A "new glucoside capable of 

 hydrolysis by emulsin, scabiosine. This glucoside was 

 extracted from the root of Scabiosa succisa (devil's 

 bit scabious). Details of its isolation and hydrolysis 

 by dilute sulphuric acid and by emulsin are given. — 

 A. Ratean : The flight altitude which corresponds to a 

 minimum consumption of petrol per kilometre, and 

 the calculation of the best propeller for a given aero- 

 plane. — A. Righi : The experimental bases of the 

 theory of relativity. — A. Mesnager was elected a 

 member of the section of mechanics in succession to 

 the late Marcel Deprez, and A. Fowler a correspondant 

 for the section of astronomy in succession to the late 

 Edmund Weiss. — N. E. Norlund : The convergence of 

 certain series. — A. Rosenblatt : A theorem of A. 

 Liapounoff.— M. T. Huber : A rational theory of 

 Passing in reinforced concrete, considered as t"hin 

 plates.— Ch. Fremont: The resistance of steels to 

 cutting bv tools. It is well known that steels pos- 

 sessing the same resistance to fracture by tension 

 may differ greatly in the ease with which thev can 

 be cut by tools. Instead of the usual calculation, 

 maximum load divided by iViitial cross-section, the 

 author proposes the term ''final resistance," obtained 

 by dividing the maximum load by the actual cross- 

 section of the broken test piece.— J. Gnyot and L. J, 

 NO. 2632, VOL. 105] 



Simon : The combustion of methyl esters with a 

 mixture of sulphuric and chromic acids. Analytical 

 figures are given for the wet combustion of sixteen 

 methyl compounds of different types, and the carbon 

 dioxide produced is shown to be practically theoretical. — 

 A. Maillie and F. de Godon : The preparation of fatty 

 acids by the catalytic oxidation of the primary alcohols. 

 With reduced copper as catalyst, and at temperatures 

 between 260° C. and 270° C., the primary alcohols 

 with air give substantial yields of the corresponding 

 acids. Aldehydes are always produced at the same 

 time, and in some cases more aldehyde than acid is 

 produced.— C. Schlumberger : Attempts at the electrical 

 prospecting of the subsoil. — Mme. Z. Gruzewska : 

 Contribution to the study of laminarine from 

 Laminaria flexicaulis. Laminarine cannot be con- 

 sidered as belonging to the dextrin group, having 

 regard to its laevorotatory power and its resistance to 

 the action of acids and alkalis. Its digestibility by 

 the plant diastases shows it to be a reserve material 

 in the marine algae. — A. Sartory : A new fungus of 

 the genus Aspergillus isolated from a case , of 

 onychomycosis. — H. Pi^ron : The variation of energy 

 as a function of the time of stimulation for foveal 

 vision. — A, Vernes and R. Donris : The action of 

 certain precipitates on the solution of the red blood 

 corpuscles. — R. Antliony : The exorchidia of Meso- 

 plodon and the re-ascent of the testicles in the course 

 of the phylogeny of the Cetaceans. — J. L. Lichten- 

 stein : The parasitism of Aphiochaeta (Phora) fasciata. 

 — E. F. Galiano : Some histological details of the 

 arterial heart of Sepia officinalis. — G. Riqnoir : Col- 

 loidal complexes and sera. A preliminary injection of 

 a colloid, followed after an interval by an injection of 

 a curative serum, may produce beneficial eflfects in 

 cases where the serum injection alone has proved to 

 be without effect. Several examples are detailed. — 

 A. Trillat : The influence of the variation of the 

 barometric pressure on the microbial droplets in sus- 

 pension in the atmosphere. 



Books Received. 



A Geographical Bibliography of British Ornithology. 

 Bv W. H. Mullens, H. Kirke Swann, and Rev, 

 F! C. R. Jourdain. Part iii. Pp. 193-288. (London: 

 Witherbv and Co.) 6s. net. 



Aristotle. By Dr. A. E. Taylor. Revised edition. 

 Pp. 126. (London and Edinburgh : T. C. and E, C. 

 Jack, Ltd.) IS. 3d. net. 



Wireless Telegraphy and Telephony. By H. M. 

 Dowsett. Pp xxxi-f33i. (London : The Wireless 

 Press, Ltd.) gs. 



Wireless Transmission of Photographs. By M. J. 

 Martin. Second edition. Pp. xv+143. (London: 

 The Wireless Press, Ltd.) 55. 



Selected Studies in Elementary Physics. Bv E. 

 Blake. Pp. viii+176. (London: The Wireless Press, 

 Ltd.) 55. 



Volumetric Analysis. By J, B. Coppock. Revised 

 and enlarged edition. Pp. 100. (London : Sir I. 

 Pitman and Sons, Ltd.) 3s. 6d. net. 



A Map of the World (on Merca tor's Projection), 

 having Special Reference to Forest Regions and the 

 Geographical Distribution of Timber Trees. Prepared 

 by J. H. Davies. (Edinburgh : W. and A. K. John- 

 ston, Ltd. ; London : Macmillan and Co., Ltd.) 8."?, 

 net. 



A Foundation Course in Chemistry. By J. W. 

 Dodgson and J. A. Murray. Second edition. Pp. xii-»- 

 240 + Answers. (London: Hodder and Stoughton, 

 Ltd.) 65, 6d. net. 



