REVIEWS 187 



Rubber and Rubber Planting. By R. H. Lock, Sc.D. [Pp. xiv + 246, 10 

 plates and 18 text figures.] (London : Cambridge University Press, 1913. 

 Price 55-. net.) 

 THOUGH no other vegetable product has been put to so many and varied uses as 

 rubber, and none has risen with equal rapidity from insignificance to such high 

 commercial importance, the science and practice of rubber planting are alike, as 

 the author points out, still in their infancy. Dr. Lock is to be congratulated on 

 having succeeded in compressing into the small compass of this handy and well- 

 illustrated book a remarkably complete summary of what is accurately known in 

 both the botanical and the commercial branches of the subject. His well-known 

 researches on the physiology of latex, together with his close and long-continued 

 personal acquaintance with the plantation industry in Ceylon, render the present 

 work authoritative and accurate in both branches, while it is written in a simple 

 and attractive style which should ensure a wide circle of readers. 



The subject of rubber and its cultivation is one that appeals not merely to those 

 connected with the rubber industry, but to all who are interested in natural pro- 

 ducts and particularly in one like rubber, in the development of which British 

 invention and British capital may be said to have played the predominant part 

 almost throughout. The first patent for the employment of rubber for anything 

 further than such uses as the removal of pencil marks dates back only to 1791, 

 when it was applied to waterproofing purposes by Thomas Hancock, of the firm of 

 Charles Macintosh & Co. ; but the modern extensions of rubber manufacture only 

 became possible after the discovery of vulcanisation — the process of combining 

 rubber with sulphur — was made, about seventy years ago, independently and almost 

 simultaneously by Goodyear in America and Hancock in England. In his chapters 

 on the chemistry of rubber and the manufacture of rubber goods the author gives 

 details concerning vulcanisation, which ranks among the most important of all 

 industrial discoveries, since it not only makes rubber practically unaffected by 

 changes in temperature and immersion in water, but enables the manufacturer to 

 vary the physical properties of the finished product, according to the proportion of 

 sulphur used, from those of the softest elastic up to those of the hardest vulcanite. 

 The importance of the rubber-planting industry to this country may be gauged 

 from the fact that over ^100,000,000 of British money are invested in it, quite apart 

 from the almost innumerable manufacturing industries in which rubber plays a part. 

 The author discusses the botanical sources of rubber, the physiology of latex 

 production, and experiments in tapping ; then follow four chapters on Hevea 

 brasiliensis, dealing respectively with planting and harvesting operations, factory 

 work on the estate, and the pests and diseases of Hevea. A chapter is next 

 devoted to the cultivation of rubber-yielding plants other than Hevea, in which, 

 after a brief but judicious summary of the results obtained from Castilloa,Manihot, 

 Funtumia, and Ficus elastica in various parts of the tropics, he arrives at the con- 

 clusion that in the future the world's supply of rubber will probably depend more 

 and more upon the Hevea plantations. The chapter on rubber chemistry gives a 

 remarkably clear and concise account of recent work on a substance whose 

 chemical composition and behaviour are among the most difficult problems facing 

 the organic chemist. F. Cavers. 



The Diseases of Tropical Plants. By Melville Thurston Cook, Ph.D. 

 [Pp. vi + 317.] (London : Macmillan & Co., 1913. Price 8s. 6d.) 



The rapid growth of plantation industries in the tropics, and the great advances 

 made in tropical agriculture generally, within comparatively recent years have 



