2.98 



NATURE. 



[November 7, 1912 



emphasises is lliat education sliould be made more 

 practical, not only in technical institutes, but also in 

 primary and secondary schools. Among special re- 

 commendations made in the report, the following may 

 be noted : — (i) That the present system under which 

 Slate technical scholarships are granted to Indians lor 

 education in technical institutions in England and else- 

 where should be discontinued. That suitable stipends 

 should be granted to Indians who have completed 

 successfully their theoretical and practical education in 

 India to enable them to be apprenticed for practical 

 e.Kperience with firms of repute in England. (2) That 

 minor technical institutes should be placed under the 

 control of one central institution in each province. 

 (3) That the education of skilled workmen sliould only 

 be carried up to vernacular reading, sufficient elemen- 

 tary arithmetic for accounts and sufficient knowledge 

 of drawing to understand a dimensioned sketch. (4) 

 That the most promising method of training skilled 

 worlcmen is to establish manual training schools for 

 children in big centres and near big workshops; the 

 boys to be apprenticed in workshops from the ages 

 of twelve to fourteen years. During the apprentice- 

 ship they are to be obliged to attend afternoon classes 

 to complete their literary education, and finally to 

 obtain some theoretical knowledge of their work. 



SOCIETIES AND ACADEMIES. 

 London. 



Institution of Mining and Metallurgy, October 17 



Mi. Edward Hooper, president, in the chair. — J. W. 

 Ashcroft : The flotation process, as applied to the con- 

 centration of copper ere at the Kyloe Copper Mine, 

 New South Wales. As a consequence of the oxidised 

 ore at this mine being practically exhausted, the 

 original method of treatment was found to be in- 

 adequate, and the present management introduced an 

 experimental flotation process with the view of obtain- 

 ing a better recovery and higher grade concentrate. 

 As first planned, the plant for this flotation process 

 was divided into a grinding section and a flotation 

 section, and the paper deals at length with tlie defects 

 which manifested themselves in tlie first experimental 

 stages, and with the rearrangements dictated by ex- 

 perience. The cliief defects were the excessive 

 amount of oversize in the feed of the stirring boxes, 

 the excessive dilution of the pulp, the irregularity of 

 the overflow from the flotation chambers due to the 

 irregularity of the feed and of the speed of the im- 

 pellers, and a want of proper means to control the 

 supply of oil. To remedy these, the grinding pans 

 were altered to the positive feed type, and were 

 arranged to discharge on to revolving screens, so as to 

 keep the feed to the flotation machine more even in 

 size ; the pulp thickener was moved and placed be- 

 tween the screens and the flotation machine so as to 

 keep an even feed to the stirring boxes and to regulate 

 its densitv; the flotation machine was controlled by 

 a sensitive governor to keep the speed of the stirrers 

 constant, and an aonaratus was devised to secure an 

 even flow of oil. The results of this reorganisation 

 proved satisfactory, and this paper gives interesting 

 details of costs of operation, &c., and some observa- 

 tions on the successful working of the process. 



Physical Society, October 25.— Prof. C. H. Lees, 

 l''.R.S., vice-president, in the chair. — Prof. H. 

 Nagaoka and T. Takamine : The constitution of mercury 

 lines examined by an echelon grating and a Lummer- 

 Gehrcke plate. The authors have photographed the 

 principal lines of mercury, using an echelon spectro- 

 scope crossed by a Lummer-Gehrcke plate. They find 

 that the 5700 line consists of eight, the 5769 

 line of four, the 5461 line of nine, the 4359 

 NO. 2245, VOL. 90] 



of eleven, the 4078 of six, and the 4047 of 

 seven components, the positions of which in general 

 agree with those found by recent observers. They 

 point out a simple relation between the distances of 

 tile components from the principal line in each case, 

 and a further relation between the quotient of each of 

 these distances by the w^ave-length of the principal 

 line, which holds for all the lines. — Prof. H. Nagaoka : 

 Note on the mutual inductance of two coaxial circular 

 currents. Methods are given for the rapid calculation 

 of the mutual inductance of two coaxial circular cur- 

 rents. Maxwell's first formula is converted into theta- 

 functions, and then expanded in a Jacobian q series. 

 The logarithmic values of this series for various values 

 of q have been tabulated in a previous paper by the 

 author. When the circles are near one another a 

 series for M is given in terms of q^, w'here q^ is the 

 complement of g. In tffis paper the author treats 

 Maxw-ell's second formula in a similar way. A table 

 of the values of these series found, computed to si.\. 

 decimal figures by T. Tishima, is given. — S. E. Hill : 

 The absorption of gases in vacuum tubes. This paper 

 is an account of experiments carried out to determine 

 whether the absorption of gases caused by passing a 

 discharge for some time through vacuum tubes is the 

 result of a chemical action or is a mere physical 

 absorption. In order to eliminate all electrode com- 

 plications, tlie electrodeless discliarge was used 

 throughout. The bulbs examined were of soda, lead, 

 Bohemia and Jena glass. The absorptions were noted 

 at different pressures and curves plotted. Continued 

 passage of a discharge causes a " saturation " effect in 

 all the glasses. After two months none of the bulbs 

 had recovered any of their absorptive power. That 

 chemical actions are present is shown bv peculiar 

 deposits on the necks of the bulbs, these being un- 

 fortunately too small for analysis. The conclusioir 

 arrived at is that the disappearance is not due to 

 physical absorption, but to definite chemical action. 

 Manchester. 



Literary and Philosophical Society, October 15.— Mr. 

 Francis Jones, vice-president, in the chair. — A. Adam- 

 son : An apparatus which can be used for the exact 

 tiisection of an angle. — D. M. S. Watson : The larger 

 Coal Measure amphibia. The author described the 

 skulls of Loxomma Allmani and Anthracosaurus 

 RiisscUi (Pteroplax), now preserved in Newcastle-on- 

 Tyne Museum. The skulls had been previously de- 

 scribed by Embleton and .Atthey, but the important 

 structure of the palate had not been made out. This 

 was described in detail, and compared with that of 

 other Carboniferous amphibia. It was shown that a- 

 solid, bony palate, with an articular connection be- 

 tween the large pterygoids and the basisphenoid was 

 characteristic of the group. The palatines and pre- 

 vomers bear large teeth with a characteristic mode of 

 replacement. The pre-maxillae and maxilte are con- 

 fined to the margin of the palate, and bear smaller 

 teeth. The large vacuities of the later Stegocephalia 

 are absent. The skulls present remarkable resemblance 

 to those of Seymouria and also of the Crossoptery- 

 gian fishes. The relations of the quadrate were clearly 

 determined, and seemed to indicate that the tetrapod 

 skull was not autostylic in the ordinary sense. 

 Paris. 



Academy of Sciences, October 28.— M. Lippmann in 

 the chair. — E. Jungfleisch : Inactive and racemic dilac- 

 tylic acids. The crude acid arising from the interaction 

 of sodium ethvl lactate and ethvl a-rhloropropionate is 

 neutralised with magnesium hydroxide. The inactive 

 magnesium salt, being much less soluble in hot or 

 cold water than the racemic form, separates first. 

 The crystallographic properties of these salts , and of 

 the corresponding acids are described. — F^douard 



