,2.36_ 



NATURE 



[October 21, 1920 



habits, in habitat, and in geographical distribu- 

 tion. The "Teredo," as so designated by the 

 engineer, may comprise at least some twenty or 

 thirty different species. Some thrive in brackish 

 water ; others do not ; Teredo navalis is intolerant 

 of it. NausUora Dunlopei, a tropical species, com- 

 monly lives in perfectly fresh water. Generally, 

 it has been found that timber piles in muddy, or 

 sewage-contaminated, water are least subject to 

 attack, from which it seems evident that ship- 

 worms require clear and fairly pure water for their 

 effective development. Notwithstanding the ad- 

 vantage derived in certain cases by the treatment 

 of timber with creosote, it is noteworthy that no 

 completely protective antidote has been dis- 

 covered. Greenheart is the timber which offers 

 most effective resistance to attack. 



The corrodibility of iron and steel is a branch 

 of the subject admitting of but slow deternfiina- 

 tion, so-called "acceleration tests," having proved 

 untrustworthy. The percentage of impurities and 

 the precise composition of alloys are of funda- 

 mental importance. The first effect of chromium 

 is that of increasing corrosion, but a further addi- 

 tion effects a retardation. Sir Robert Hadfield 

 has informed the committee that he is experi- 

 menting with an aJloy of iron and chromium 

 which manifests considerable resistance to sea- 

 water corrosion. The committee details certain 

 arrangements which they have made with Sir R. 

 Hadfield and Dr. Friend for testing the rate of 

 corrosion of medium carbon steel, mild steel, 

 " Galahad " non-corrosive steel, nickel steel, 

 Swedish charcoal, iron, and cast iron. The dura- 

 tion of the experiments may extend to twenty years. 



The most important findings of the committee 

 include the following : Creosoting as a protective 

 treatment for Baltic timber is justified at the home 

 ports, but not in tropical waters ; reinforced con- 

 crete is a more suitable material for adoption 

 where the sea-worm is very active ; and ordinary 

 concrete, whether in block form or in mass, pro- 

 duces thoroughly permanent work, if carried out 

 in the properly specified manner. 



Brvsson Cunningham. 



Tropical Disease and Administration. 



War against Tropical Disease: Being Seven 

 Sanitary Sermons addressed to all interested 

 in Tropical Hygiene and Administration. By 

 Dr. Andrew Balfour. Pp. 219. (London: 

 Baillifere, Tindall, and Cox, 1920.) Price 

 i2i. 6d. net. 



AN essential in medical treatment is that the 

 patient shall have faith in the professed 

 healer; his rulings must be accepted as well as 

 NO. 2660, VOL. IC6] 



his drugs.. -Hence, in a period when empirical 

 observations were the necessary substitute for 

 scientific investigation, occasionally it might not 

 have been conducive to the bodily safety of the 

 physician w-ere the patient to doubt the soundness 

 of the deductions therefrom. .Argument was there- 

 fore successfully evaded by an assumption of 

 mystery too deep for ordinary mortals to fathom ; 

 drug roots were gathered with incantations by 

 moonlight — the fever-stricken patient submitted 

 to being deprived of a breath of fresh air. With 

 the physician of the present day, so far as drugs 

 are concerned, the awe inspired by mysticism to 

 some extent remains ; professional ethics — to the 

 advantage of the patient — ordain secrecy, but the 

 crude rulings of the past have been superseded by 

 the dicta of the science of hygiene, which insist 

 that "prevention is better than cure." Its de- 

 votees demand, not professional mysticism, but 

 world-wide propaganda. Nowhere, in the interests 

 of life, is this more necessary than in those por- 

 tions of the world vaguely termed the "tropics," 

 W'here even useful, though ancient, empirical sani- 

 tary deductions have been forgotten, or have 

 become inapplicable in the press of life accom- 

 panying modern civilisation. 



It is a matter of common experience that whilst 

 the average educated layman is capable of dis- 

 cussing the role of certain mosquitoes, flies, fleas, 

 lice, and licks in the spread of disease, he fails 

 to understand that, not only philanthropy, but 

 also the prosperitv of commerce, facilities for 

 intercommunication with areas supplying raw- 

 material and the availabilitv of suitable labour 

 therefor, very largely depend upon the preventior* 

 of preventable diseases in the tropics. Hence, if it 

 were possible to convey to the busy layman where 

 action is requisite and what measures are ap- 

 plicable, undoubtedly a great impetus would be 

 given to applied hygiene. To this end that well- 

 known authority upon sanitation in the tropics. 

 Dr. Andrew Balfour, director of the \\'ellcome 

 Bureau of Scientific Research, London, has 

 written the work under notice. 



The larger part of this work is occupied by a 

 record of travels in .Africa, Mesopotamia, the 

 West Indies, and South America. Inter alia, 

 much interesting information is given as to make- 

 shift sanitary methods employed during the late 

 war. The final chapters deal with the necessities 

 and measures requisite for the central administra- 

 tion of public health, as exemplified by a sug- 

 gested Ministry of Health for Egypt on lines 

 proposed by a Commission appointed for that 

 purpose. 



Throughout the lightly written and interesting 

 pages of this book Dr. Balfour has steadily main- 



