14 



-/^Ap¥m 



{M'AY 1-6, i9^S 



wj(iile ttke terrhs^idf kigHer order acc»rd pretty fa|rly on 

 \i}i^ whple with Schu§te,r^s hypothesis, this is hot true 

 o(„ the, principal terms of lower order. The natural 

 inference is that the hypothesis is, at best, riot a com- 

 plete , explanation of the phenomena. To the second 

 question the answer obtained is that the forces causing 

 the, diurnal variation do not possess a potential; part, 

 hut only part,, of the diurnal variation may be derived 

 f,rom a potential. Besides the main data mentioned 

 abPiV^, data from.a number of other stations are utilised, 

 and- there is, besides, a good deal of mathematical 

 theory. While the publication makes most direct appeal 

 to theorists, it contains much valuable information as 

 to> facts not otherwise readilv accessible. 



,. 1 GALVANOMETRIC RECORDS OF 

 Gr,i .;!;,' EMOTIVITY. 



IN' the correspondence columns of the issue of the 

 Lancet for February 23, Dr. A. D. Waller 

 described some very interesting results which he had 

 obtained by the study of the " emotive response " 

 or "psycho-galvanic reflex" on various individuals. 

 H, by means of electrodes applied to the 

 dorsum and palm of the hand, a subject be 

 connected in series with two Leclanch^ cells and 

 a galvanometer, an emotive response is shown by 

 the deflection of the latter, not only to physical stimuli 

 suth as burning, unexpected noise, smell {e.g. a poison 

 gas), but iaiso to psychical stimuli such as apprehension, 

 questions, and thoughts, pleasant or unpleasant. The 



, FiQ. I.— Galvanometric recprd of Miss G. De D. during the air raid 

 of January 29, 1918. At the tenth minute of observation the 

 noise ot maroons, immet^ lately followed by that of aeroplanes 



, and guns, broke out, and the resistance, which was approxi- 

 mately 60,000 ohms during the first ten minutes before the 

 disturbance, fell to .ipproximately 20,000 ohms during the next 



; fifteen minutes. (On the left hand is given the resistance in 



1 thousands of ohms.,J 



normal resistance between the back and the palm of 

 the hand is between 10,000 and 40,000 ohms. 



From many experiments made on different subjects, 

 besides the big variation in actual resistance there is 

 a marked difference in emotive response; also in the 

 change of resistance which takes place during an ex- 

 periment, and in the response of the subject to the 

 same stimulus at different stages of the experiment. 

 In some individuals a greater physiological change may 

 be caused by. an imaginary than by a real excitation. 

 This- is especially the case in imaginative subjects, 

 such as members of the literary, artistic, and scientific 

 professions. A very interesting record (Fig. i) is given 

 oi the -response of a subject taken during an air raid.^ 

 v.'fCornparative records are also given of two officers,! 

 one of high and the other of normal emotivity. It' 

 NO. 2533, VOL. lOl] 



: would be 'of"' extr^rhe' 'interest '^o know the natprje' of 

 ; resporise in a Series of subjects Who' have siicci^ssfulfy 

 i withstood niany nierve-trying ordeals — ^as, for example, 

 I the respbhse of the experienced and successful fighting 

 ai{--pllot. it is possible that this test would be of 

 value in special cases in the selectiort of air-pilots, 

 ! and also invaluable to the military authorities as an 

 I adjunct to the ordinary medical examination in 

 j classifying doubtful "'nerve" cases, e.g. shell-shock, 

 I neurasthenia, and malingering. 



ATMOSPHERIC POLLUTION. 



A N examination of the third report of the Advisory 

 **■ Committee on Atmospheric Pollution, published 

 as a supplement to the Lancet of March 23, shows 

 that the total deposit for 1916-17 has increased in 

 the (six) summer months over that of the previous 

 year, which was greater than that of 1914-15, so 

 that 'there .has been a steady increase in most of the 

 stations during the past three years. On the other 

 hand, in the (six) winter months a diminution in 

 1916-17 is recorded. No very definite conclusions can 

 be drawn from these results, as the stations have in 

 some cases been changed; but in London, where the 

 same stations have been in steady operation during 

 this period, there is a distinct improvement in the 

 winter months, and the same is true of Glasgow. 



Among the towns exhibiting the highest deposits of 

 atmospheric impurities St. Helens and Glasgow stand 

 out most prominently, whilst Malvern and Exeter, as 

 might be expected, exhibit the lowest figures. 



A comparison of deposits during wet and dry 

 weather indicates that, whereas insoluble matter is 

 little affected by rainfall, soluble matter is brought 

 down in much larger amount. The highest and 

 lowest deposits, based on the average of eighteen 

 stations, correspond, nevertheless, in no instance with 

 the highest and lowest rainfall. 



Some kind of automatic recorder for the rapid regis- 

 tration of atmospheric pollution, to replace the cumber- 

 some and tedious method at present used, has always 

 been a great desideratum. Dr. J. S. Owens describes 

 in the present report a simple form of such an ap- 

 paratus, -whereby a known volume of air (2 litres) 

 is drawn at a fixed rate through an aperture (^ in.) 

 into which a piece of filter paper is inserted. The 

 stain produced by the arresited dust particles gives a 

 measure of the amount of suspended impurity, and 

 by calibration with weighed quantities, which have 

 been determined toy Mr. J. G. Clark, the depth of 

 deposit can be expressed quantitatively. The method 

 appears to give trustworthy results, and each deter- 

 mination is complete in ten minutes. It does not, 

 of course, touch the gaseous impurities, but as these 

 run to a great extent parallel with the solid impuri- 

 ties, and as the latter are the more injurious, the 

 results should give a fair record of the changes taking 

 place in atmospheric pollution at different centres. 

 As the method involves simple apparatus and but 

 little attention, it is to be hoped that a larger number 

 of observers will be induced to enrol themselves under 

 the present committee. J. B. C. 



LUBRICATING OILS. 



TN a paper read by Drs. A. E. Dunstan and F. B. 



^ _ Thole before the Institution of Petroleum Techno- 

 logists on April 16, the authors, in reviewing the work 

 of previous observers, point out that little knowledge 

 exists as to the chemical composition of lubricating 

 oils and the relation between their diemical character 

 and lubficating properties. These 'oils probably con- 

 sist (though nothing^:,yery ide-ftnitfi, is., known) of 



