538 SCIENCE PROGRESS 



The illustrations are good, all are of practical value, and each shows striking 

 points in the technique. 



The introductory chapter deals with the X-ray tube, the physics of this subject 

 being briefly entered into. The importance of a fine focus point in the tube is 

 emphasised. The chapter ends with a description of the Coolidge tube. 



X-Ray Stereoscopy. — The details of the method are well described. An im- 

 portant matter is discussed under the heading "The Misleading Single Picture." 



The works of Wheatstone, Brewster, and Le Comte are recommended to those 

 who are interested in the principles underlying stereoscopy. The vertical ray is 

 employed in stereoscopic work, and the methods of selecting and utilising it are 

 well described, as is also the subsequent arrangement of the negatives for the 

 examination of the radiographs in the stereoscope. 



Chapter IV. deals with rapid X-ray localisation, a subject of the utmost im- 

 portance at the present time. A new couch adapted to the requirements of rapid 

 localisation is illustrated and described. It is light, portable, and can be readily 

 constructed by any one who can handle tools. 



The measurement of the displacement of the shadow of the foreign body on 

 the screen is next described. This rapid method is valuable in times of stress 

 when many cases have to be done quickly. 



The author next deals fully with the cross-thread method of measuring. 

 Elementary facts in geometry are utilised to simplify the explanation, and a 

 number of instructive drawings are included in the text. 



This is one of the best chapters of the book, and should be read carefully by 

 all workers who desire to grasp the principles of localisation by this method. 



The localisation of foreign bodies in the eyeball and orbit is dealt with in 

 full. This is, as would be expected, the most instructive section of the book. The 

 method is fully described, and a number of instructive stereoscopic photographs 

 employed to render the text as clear as it is possible to make it. 



An important piece of auxiliary apparatus is described in Appendix I. — the 

 Telephone Attachment in Surgery. This should be read by all surgeons who 

 have to deal with foreign bodies in the human frame. 



A most instructive appendix on the localisation from a single photograph is a 

 feature of the book. This is most clearly written, and illustrates how from a single 

 plate all the data necessary for the guidance of the surgeon may be obtained. 



The author concludes the book with a short appendix on the rectification of the 

 current supplied to the X-ray tube. 



The publication of a book on localisation by X-rays and stereoscopy at the 

 present time will be welcomed by all who are engaged in X-ray work in connection 

 with the war. Operating surgeons will find in its pages a lucid and instructive 

 description of the original method of localisation which must greatly aid them in 

 the interpretation of the X-ray plates of their cases. 



Milk and its Hygienic Relations. Medical Research Committee Series. By 

 Janet E. Lane-Claypon, M.D., D.Sc. [Pp. viii + 348.] (London: 

 Longmans, Green & Co. Price 7s. bd) 



The Medical Research Committee under the National Health Insurance Act 

 entrusted to Dr. Janet Lane-Claypon an important investigation into milk and its 

 hygienic relations. No article of food is of greater importance, nor more widely 

 used, at all ages, in health and in sickness, and it is not surprising therefore that, 

 notwithstanding the many treatises written upon the subject, and the great attention 

 given to it, there is still room to reward the further investigations by the author. 



