November 12, 19 14] 



NATURE 



277 



sanitary authorities have estabUshed " tuberculin 

 dispensaries," where it may l)e applied to the 

 poorer population under adequate medical super- 

 vision. On the other hand many Continental 

 authorities view tuberculin treatment with con- 

 siderable distrust. The appearance of Dr. 

 Bardswell's report is therefore opportune, and we 

 could have hoped that experience in the King" 

 Edward \'II. sanatorium might have settled the 

 real value or otherwise of tuberculin in the treat- 

 ment of consumption. Some of the data obtained 

 seerh to be in favour of it, but Prof. Karl Pearson 

 has examined the statistical data, and concludes 

 that they do not show " that obvious and marked 

 advantage of tuberculin treatment which would 

 raise it at once above all suspicion of showing" 

 what advantage it does show, owing to selection 

 of patients. Correction for selection may show 

 it with a slight credit or an actual debit. . . . 

 When all selected cases are treated as at present, 

 we shall ha\e no suitable control to determine 

 whether the treatment has any real value, unless 

 indeed we again leave it off." ^^'e notice that 

 X-ray photographs do not appear to be a routine 

 method of examination at this sanatorium, which 

 is surprising, and Spengler's picrin method for 

 staining the tubercle bacillus might be adopted 

 with advantage. 



(2) This book on isolation hospttals must be 

 regarded as an authoritative one, as Dr. Parsons 

 was a recognised authority on the subject. The 

 past tense is used because the author did not 

 live to see the work through the press, and its 

 correction and completion was undertaken by Dr. 

 Bruce Low. The book contains far more than its 

 title indicates, as it really deals with the whole 

 question of isolation for the preventive treatment 

 of infective diseases. Thus in addition to isola- 

 tion hospitals, the subjects of home isolation, 

 eucalyptus treatment, and the law in relation to 

 infectious diseases are fully discussed. Under 

 isolation hospitals, the subjects of area, site, de- 

 sign, staffing, removal and discharge of patients, 

 and cost are dealt with. Additional chapters are 

 devoted to the hospital system of the Metropolitan 

 Asylums Board and sanatoria for tuberculosis. 

 A number of plans with descriptions of existing 

 isolation hospitals complete the work, which 

 should be of the greatest value to public health 

 students and authorities. 



(3) Dr. Savage has brought together into one 

 volume a mass of valuable data relating to the 

 bacteriology of foods, water, air, soil, and 

 sewage, together with a description of the 

 methods employed for examining them bacterio- 

 logically. He himself has contributed much to 

 the subject, and is therefore able to discuss 



NO. 2350, VOL. 94] 



critically the value of the various methods em- 

 ployed, and of the data obtained therefrom. In 

 a final chapter the determination of antiseptic and 

 germicidal power is described, and the composi- 

 tion of the media employed is given in an 

 appendix. The book is a very useful addition to 

 the Cambridge Public Health Series, which is now 

 being issued under the editorship of Dr. Graham 

 Smith and Mr. Purvis. R. T. Hewlett. 



LIGHT AND ITS ACTIONS. 

 (i) Photo-Chemistry. By Dr. S. E. Sheppard. 



Pp. X + 461. (London: Longmans, Green and 



Co., 1914.) Price 125. 6d. 

 (2) Photo-Electricity. By Prof. A. LI. Hughes. 



Pp. viii -1-144. (Cambridge: University Press, 



1914.) Price 65. net. 



THE interest of scientific workers in the 

 chemical and physical changes brought 

 about by light is shown by the number of works 

 recently published bearing on this subject. The 

 importance of investigations on the action of light 

 can scarcely be over-estimated, seeing that human 

 life is dependent on " that branch of applied photo- 

 chemistry which is termed agriculture." 



(i) Dr. Sheppard gives an account of the prin- 

 cipal facts relating to photo-chemistry, and dis- 

 cusses the present state of the theory of the 

 subject. The book is very unequal. So far as 

 the facts are concerned, the description is gener- 

 ally clear, but in the more theoretical f>ortions 

 the author frequently runs amok and indulges in 

 quasi-philosophical discussions which do not add 

 to the lucidity of his argument. The work, un- 

 fortunately, justifies the complaints made against 

 the literary style of many men of science. Thus 

 on p. 229 we have a sentence containing fifteen 

 lines, and on the following page a sentence of 

 fourteen lines. The author has a predilection for 

 the use of foreign words and for the introduction 

 into his subject of new terms which are often 

 only vaguely defined, if defined at all. We do 

 not recognise "temps" as an English word, and 

 do not regard mass and measure as interchange- 

 able terms, though the author sp>eaks of " Radiant 

 Energy in .Absolute Mass." 



In spite of many faults of presentation the 

 volume will be found useful, as it contains a large 

 amount of matter not available in other English 

 works. The first half of the book deals with the 

 physical side of the subject, and includes chapters 

 on the measurement of light quantities, the 

 energetics of radiation, and the absorption of light. 

 .\ctual light-sources are also considered, special 

 attention being given to the light of the sun, 

 either in its direct form or as diffused daylight. 

 The mercury vapour lamp scarcely receives ade- 



