September 26, 1907] 



NATURE 



541 



time lecture xiii. is reached, the evidence is over- 

 whelming as to the extent of hysterical symptoms and 

 the ground of their relationship to one another. 

 " Dissociation " and " suggestibility " are the words 

 employed to describe the underlying mental state, and 

 their exact meanings are very carefully and thoroughly 

 worked out. The final outcome is a definition of 

 hysteria, an enumeration of its direct and indirect 

 stigmata, and incidentally a theory as to the nature 

 of personal synthesis, with which this disease is so 

 closely connected. 



To medical practitioners and psychologists alike the 

 work should be of supreme value. W. B. 



THEORY AND PRACTICE OF LUBRICATION. 



Lubrication and Lubricants. .4 Treatise on the 

 Theory and Practice of Lubrication, and on the 

 Nature, Properties, and Testing of Lubricants. 

 By Leonard .Archbutt and R. Mountford Deeley. 

 Second edition, thoroughly revised and enlarged. 

 Pp. xxxii + 528. (London : C. Griffin and Co., Ltd., 

 1907.) Price 2 IX. net. 

 ' I 'HIS work may be divided into two parts, which, 

 -I- in fact, have little connection with one another. 

 The first is that which deals with the chemical and 

 physical properties of lubricants generally, and will 

 appeal more particularly to analytical chemists, to 

 whom samples of lubricants are submitted for the 

 purpose of estimating their commercial value. So 

 far as one can judge, this part of the work is par- 

 ticularly clear ; full directions are given for carrying 

 out any of the tests, in order to obtain such things 

 as the free acids. This will, however, hardly appeal 

 to the average user of lubricants, as what he requires 

 is some simple mechanical test which will, more or 

 less, indicate the value of the oil. The second portion 

 of the work deals with the mechanical testing of oil, 

 and also the design and construction of bearings 

 generally, together with the general theorv of fric- 

 tion, as given in chapter iv. This is particularly well 

 written, and gives the full theory of lubrication as 

 developed by Osborne Reynolds, Goodman, and 

 Towers, and will repay a careful study. An account 

 is given of the various oil-testing machines as designed 

 by Thurstan, Smith, and Goodman. Judging from 

 our own experience, while these machines when 

 extremely carefully handled give trustworthy results, 

 one is never quite certain as to what is really being 

 obtained ; whether it is a test of the lubrication itself, 

 of the materials forming the bearing, or of the 

 condition of the bearing. We should be inclined to 

 say that it would probably be a small part of each, 

 and, moreover, it does not give much idea as to the 

 value of the lubricant for continuous use, which is 

 now the rule for engine work generally. Doubtless, 

 owing to the great length of the book, some 500 

 pages, the authors have been unable to devote a large 

 space to the design and lubrication of bearings, 

 although they give much useful information as to the 

 composition of bearing metals generally, and also the 

 admissible loads. They do not, however, give the 

 attention to forced lubrication which we consider it 

 NO. 1978, VOL. 76} 



deserves. The whole tendency of modern engine 

 practice, either with enclosed or open engines, is to 

 substitute pressure lubrication for gravity, and this 

 has entailed wholly different construction of bearings 

 from those with the ordinary drip lubrication. 



The large subject of ball and roller bearings is dis- 

 missed in some three pages, and, considering the 

 importance and growing use of the ball bearing in 

 large sizes, we think this type of bearing deserved 

 fuller attention. The mechanical lubrication by means 

 of sight-feed lubricators, which allows the attendant 

 to regulate exactly the quantity of his oil, is well 

 illustrated, and rightly so, because this method is 

 found in practice very considerably to economise the 

 oil supply. Splash lubrication, as used by Willans and 

 by many motor-car engineers, is alluded to, but its 

 defects as regards the oil working up into the motor 

 cylinders are not pointed out, nor is it shown that this 

 method of lubrication is fast being driven out in 

 favour of a pressure system. The authors, in the 

 chapter on gas-engine cylinder lubrication, give 

 some interesting analyses of the deposit found 

 in the cjlinders, and point out that the de- 

 posit is not wholly of a carbonaceous nature, 

 but contains quite a considerable portion of 

 sulphur obtained from the gas. They also re- 

 commend the use of pure mineral oils, as against the 

 mixture of a small quantity of a neutral fixed oil. 

 This wholly agrees with our own experience, namely, 

 that a pure mineral oil is the only one possible to 

 use when the compression of the engine is in the 

 neighbourhood of 200 lb. per square inch. It would 

 almost appear as if the whole difficulty of running 

 at very high compressions is to prevent deposits of 

 carbon. The only way to overcome this is to use 

 an oil which will entirely burn, and in very small 

 quantities. All those who are interested in lubrica- 

 tion generally will welcome Messrs. Archbutt and 

 Deeley's work, more especially those in a consultative 

 position, but we fear that, owing to its length and 

 the predominance of the chemical and physical side, 

 it will not be of the service to engineers generally 

 that a smaller and less scientific work would be, as it 

 must be borne in mind that the great majority of 

 those who have to use lubricants have neither the 

 time nor inclination to make accurate chemical tests. 



F. \V. BURSTALL. 



OUR BOOK .SHELF. 

 The Savage South Seas. Painted by Norman H. 



Hardy. Described by E. Way Elkington. Pp. 



xii + 2ii. (London: A. and C. Black, 1907.) 



Price 20s. net. 

 To those who know the parts of Melanesia which 

 Mr. Norman Hardy pictures, or who, like the writer, 

 have seen much of his work, this book will come as 

 something of a disappointment; and this from no 

 fault of the artist, who is generally successful in 

 reproducing, not only the physiognomy, but the mus- 

 culature and the tricks of movement of the folk 

 whom he portrays. The truth is that the tone of the 

 reproductions (apparently made by the three-colour 

 process or one of its modifications) of Mr. Hardy's 

 water-colour sketches leaves much to be desired ; in 

 many of the reproductions there is a darkening of 



