;i8 



NATURE 



[December tg, 1918 



suitable educational promise. The amounl of the 

 assistance to be granted will b< limited to the actual 

 sum deemed sufficient to meet the neces*sar\ fees and 

 in expenses of maintenance of the candidate, alter 

 due account has been taken of his private means, if 

 any. Ii is intended, however, that the amount of the 

 assistance shall be such as will enable a candidate to 

 lake his course of training undei reasonably adequate 

 conditions, 'The types of training for which assistance 

 ma) be granted are: (1) Courses of higher education 

 in institutions approved b) the Board of Education pi 

 by. the Board ol Agriculture and Fisheries, or by the 



1 sponding Departments for Scotland or Ireland; 



(2) Mich practical training in offices and works and 

 professional employments as may be approved by the 

 Ministry of Labour; and (3) such practical training 

 on farms, etc., a-> m.n be approved by the Hoard of 

 Agriculture and Fisheries, or b) the corresponding 

 Department for Scotland or Ireland. The Ministry of 

 Pensions will co-operate in the working of tin scheme 

 on behall oi disabled officers and men, who will be 

 eligible for assistance under the scheme, subject to 

 compliance with the prescribed conditions. The exist- 

 ing provisions of the Royal Warrants as to training 

 the disabled will remain in force, so far as the) may 

 be more beneficial to candidates than the provision 

 madi b\ I Ins si heme. 



SOCIETIES AND ACADEMIES. 



London. 



Royal Society, December 5. Dr. I . W. L. Glaisher, 



vice-president, in the chair. — Dr. C. Chrce : Electric 



potential gradient and atmospheric opacity at Kew 



Observatory. It has been the practice for many years 

 at Kew Observator) at the ordinary hours of meteoro- 

 logical observation to record the most distant of a 

 selected series "I objects which is visible at the time. 

 Separate notes are also made of the presence of mist 

 or fog. Thus a large amount of information has 

 accumulated as to the greater or less opacity of the 

 atmosphere. The present paper utilises the data for 

 a comparison of atmospheric opacity and the potential 

 gradient of atmospheric electricity. It is found that 

 even for tin- smallest amount of opacity which the 

 observation scheme is able to disclose, the value of 

 (lie potential gradient increases with the opacity. The 

 effect of mist or fog on the potential gradients re- 

 corded in winter is gnat, and, there being a large 

 diurnal variation in the incidence of mist or fog, there 

 is consequently a noteworthy influence on the char- 

 acter of the diurnal variation of potential gradient. — 

 E. Nevill : The value of the secular acceleration of 

 •he mean longitude of the moon. It is shown that 

 where tin- observed errors of the tabular place of the 

 moon tire properly corrected for the observed errors in 

 the values of the principal coefficients employed in 

 Hansen's Lunar Tables, the residual errors are such 

 as in show that the true value of the coefficient of the 

 secular acceleration in the mean motion of the moon 

 cannot differ sensibly from the value 6-2" assigned to 

 it b) theory, so that it affords no evidence from 

 observation of anv tidal retardation in the rotation of 

 the earth. S. R. Schryver and Nita E. Speer : 

 Investigations dealing with the state of aggregation. 

 Part iv. : The line 1 ulation of colloids b\ s.dts con- 

 taining univalent organic ions, ["he thee. ties dealing 

 with the mechanism of the action eil salts in floc- 

 culating colloids is discussed. According tee eme theory 

 the- adsorption of the' discharging ion of the- floc- 

 culating salt is the predominant action. If this is 

 the case, it might he expected that salts which cause 

 the greatest lowering of the surface tension of water 

 would exert the greatest flocculating .action where 



XO. 2564, VOL. I02] 



water is the dispersion medium. A series of salts 

 containing organic ions was chosen, of which the 

 normal solutions exhibit a wide ran-, ol surface ten- 

 sions, .and their flocculating action' em a number of 

 colloids was investigate.!. In general, no relation- 

 ship was found to exist between this action and the 

 surface tensions of the solutions, in one ease-, how- 

 ever (that of mastic), there- was a marked parallelism. 

 Attention is directed to the fact that two classes of 

 suspensoid colloids might exist. The first class com- 

 prises those colloids which owe their charge to tin ion 

 ol the sail from which the colloid is prepared, as, for 

 example, the- chlorine ion attached to a ferric hydroxide 

 sol prepared by the hydrolysis of ferric chloride. The 

 second 1 lass includes colloids in which the charge 



elite' lee a dissociated labile ion helotiging to the- colloid 



proper, held electrostatically to a less labile ion, as, for 

 example-, the mastic colloid, when a hydrogen ion (of the 

 carboxyl radicle-) is held electrostatically to a large anion. 



It is proposed to designate colloids of the first class 



eitionic, and theis.- of the- second class endionic. I . 

 Hatscliek .- A study of the forms assumed by drops 

 and vortices of a gelatinising liquid in various 

 coagulating solutions. The- paper describes a series 

 eel experiments in which drops of gelatin sol are 

 allowed to fall into various solutions. Conditions can 

 be so arranged that gelation takes place when any 

 desired shape of the hanging drop or vortex thus 

 produced has been attained. Tin- result is permanent 

 models of what tire- only transient forms when two 

 liquids are employed, as in the experimental methods 

 practised hitherto. If the solutions have a de- 

 hydrating effect on gelatin, a number of features not 

 produced at .all with liquids appear, such as > 

 rihs and membranes, or, generall) speaking, crOSS- 

 sections other than circular. The conditions can 

 further be varied by the use of solutions, or of salts 

 added to the gelatin sol, which leads to the production 

 in permeable or semi-permeable membranes on the 

 gelatin drop. By these means a further range of 

 forms can be obtained, such as bi-concave dises ,,| 

 the shape of the human red blood corpuscle, hanging 

 drop-s showing abnormal profiles and superficial se g- 

 mentation, and vortex forms greatly modified b\ 

 general shrinkage. Many of the forms obtained in 

 these experiments show a close- resemblance to thus. 

 of the simpler organisms, both as regards general out- 

 line and secondar) features. 



Geological Society, December 4. Mr. • !. W. 

 Lamplugh, president, in the- chair. Lt.-Col. WheeJton 

 Hind and Dr. A. AVilmore ; The Carboniferous succes- 

 sion of the Clitheroe province. The tectonic structure 



of tin province consists of three dissected parallel anti- 

 clinal folds in beds of Carboniferous Limestone, 

 Pendleside, and Millstone Grit age. Dissection litis 

 exposed the lower beds of Z. C, and S age, as the 

 tectonic axes and beds of D, P. and Millstone Grit age 

 occur on the flanks. The- authors give the following 

 table of Goniatite zones : — 



'■ Middle " Coal Measures Gaslri ceru cnrimariitm, von P.ue;h 

 Lower Cnal Measure* Gastriocira*ca*bmmrmm, von Buch 



Upper Mill. lone fint Ga trheeras listt«i, Ma-tin 



s.ibclen Shales Glyphiectras diadma, Beyricll 



Shales below Millstone Grit 



(Glvfihioaras bilin^ne, SaVr 

 Bowland Shales - Glvfihiaccras nticulatuw, Phillips 

 \C.hphioceras spit-alt, Phillins 

 Y=£. I Gfyfkmeras striatum, Phillips 



MS, PosidoHomxnlecluri I X.tmisnwceras •ttiforme. Phillips 



N ' Shales I Prvlecanites tomfirttsus, Snwerby 



Carboniferous l.imeseom-. To Glyphiwi rat rtnistria, Phillips 



I.innean Society, December 5. Sir David Prain, 

 president, in the 'hair. Prof. W. A. Haswell : The 

 Exogoneae. The author gives a detailed account of 

 the species occurring ttt Port Jackson of this group 

 of small Polvchtttr worms, belonging 10 the family 



= 2 l 1 



