M'ARCH i^; igio] 



BATURE 



magnetic elements should be in Greenwich time, no 

 British observatory outside Great Britain has 

 rarried out the decision. With the view of securing 

 uniformity, Dr. Bauer invites discussion of the fol- 

 Icnving- questions : Shall Greenwich time or the nearest 

 standard meridian time be used for the magnetic 

 records? Shall the mean value of an element be taken 

 from a full hour to the next or from a half-hour to 

 the next half-hour? 



.At the meeting of the Illuminating Engineering 

 Society on February 24 a discussion on " Lighting 

 Conditions in Mines, with Special Reference to the 

 Kyesight of Miners," was opened by Dr. T. Lister 

 Llewellyn, a considerable number of members of the 

 (::ouncil of British Ophthalmologists and of the 

 Ophthalmological Section of the Royal Society of 

 Medicine being present. The introductory paper dealt 

 largely with the disease of the eyes known as "miners' 

 nystagmus," the increase in which has given, much 

 concern in recent years. The disease is common in 

 coal-mines, but practically unknown in metalliferous 

 mines. Dr. Llewellyn, by the aid of statistics on eye- 

 sight, supplemented by data on the actual working 

 illumination in mines, contended that the disease was 

 mainly due to inadequate illumination; while Dr. H. S. 

 Elworthy adduced data to show that the colour of 

 the reflected light, depending chiefly on the nature of 

 the coal-surface, was also an influential factor. 

 Medical men from various mining districts enlphasised 

 the complexity of the problem, but there was general 

 agreement that illumination and the dark nature of 

 the reflecting surface in coal-mines were important 

 factors. A variety of types of miners' lamps were 

 exhibited, and Mr. E. Fudge, secretary of the Home 

 Office Committee on Miners' Lamps now sitting, 

 made some remarks on possible developments. The 

 question of whitewashing coal-surfaces in order to 

 improve the reflection of light was also considered. At 

 the conclusion of the discussion Mr. L. Gaster sug- 

 gested a comprehensive investigation by competent 

 photometric experts, aided by ophthalmic surgeons, in 

 order to obtain data on a uniform basis, establish the 

 nature of the conditions of illumination to be guarded 

 against, and consider possibilities of meeting lighting 

 requirements. 



An interesting paper on the theory and practice of 

 lubrication was read by Messrs. Wells and South- 

 combe before the London Section of the Society of 

 Chemical Industry on February 2. Free fatty acids 

 in lubricants have hitherto been judged mainly by 

 the injurious effects which they are capable of causing. 

 It has now been found, however, that these acids, In 

 strictly limited amount, can greatly increase the value 

 of mineral oils as lubricants. Tested in a Thurston 

 friction machine under conditions of very low speed 

 and high pressure, it was found that 0-5 per cent, 

 of the fatty acids of rape-oil added to a mineral oil 

 reduced the friction coefficient from o-oo66 to 00049, 

 whilst nearly 60 per cent, of the same rape-oil free 

 from acid was required to produce the same effect. 

 It appears, therefore, that this discovery affords the 

 means of -diverting to other and more useful purposes 

 ' NO. 2627, VOL. 105] 



the greater part of the saponifiable oils and fafcs' now- 

 used for blending with mineral oils. 



In a paper read to tlie Institution of Petrolei^m- 

 Technologists on February 17, Dr. W. R. Qrmandy 

 describes a number of patents which have been takerr 

 out for mixtures intended to be used as motor fuels. 

 Protesting against the present system, he states that 

 patents have been granted for admixtures of bodies^ 

 which ever>- chemist knows will mix, and every 

 engineer knows will drive an internal-combustion 

 engine. Many of them are certainly not inventions or 

 discoveries. Presumably the patents have been granted 

 because the patent records of the preceding fifty years 

 cannot show that anything of the sort has previously 

 been patented. But it is common knowledge to those 

 skilled in the matter that such liquids as paraffin,, 

 petrol, benzol, alcohol, ether, and acetone will mix 

 either in any proportion or in restricted propdrtions ;- 

 and also that by admixture, for example, of petrol 

 ^vvith benzol a certain amount of alcohol can be caused 

 to dissolve in the mixture which would not dissolve 

 in the petrol alone. It is equally common knowledge 

 to chemists and engineers that any admixture of two- 

 or more volatile fuel bodies will result in a third stib- 

 stance also capable of being used as a fuel. Disclaim- 

 ing any intention of expressing a pronounced opinion 

 on any of the specifications, the author regiirds it as 

 prejudicial to the general interests of the comrhiinity 

 that such patents should exist, and has no douW that 

 they contain the seeds of many lawsuits. ' 



We have received from Messrs. Flatters and Garnett,^ 

 Oxford Road, Manchester, their price-list of staiiis^ 

 chemicals, slides, cover-glasses, dissecting instruments^ 

 etc., for use in microscopical and histological >\'ork.. 

 The list of stains, which are all tested, seems fairly 

 complete, and the solids are supplied in quantities of 

 2^, 5, 10, and 25 grams. With a selection, of this 

 kind to choose from, the worker in these branches of 

 science should be independent of foreign suppjit^s. 



Messrs. Methuen and Co., Ltd., will publish shortly 

 a translation by Mr. R. W. Lawson, of the tlhiversity 

 of Sheffield, of "The Special and the General Theory 

 of Relativity," by Prof. Einstein. The volume is 

 primarily intended for those who are not converisant 

 with the mathematical analysis used in theoretical 

 physics, the aim of the author being to give the main' 

 ideas of the theory of relativity in the dertfest and 

 simplest form. 



A COURSE of lectures was delivered in the University 

 of London in 19 13 by Prof. E. Bresslau, of the Uni- 

 versity of Strassburg, and a volume based on' them, 

 bearing the title of "The Mammary .\pparatus of 

 the Mammalia in the Light of Ontogenesis and 

 Phylogenesis," with a preface by Prof. J. P. Hill, is 

 to be issued by Messrs. Methuen and Co., Lfd., this, 

 spring. It will provide an epitome of Prof. Bresslau's 

 investigations on the development of the milk.glands 

 and related parts in the mammalia, and of pis con- 

 clusions respecting the evolutionary history of _ the 

 marri'mary apparatus, and be fully illustrated. , 



