DURING recent years interest in the Rubber-planting industry has extended far beyond that comparatively large section of the community, which is engaged in trades more or less directly connected with rubber. In fact nowadays this material enters so intimately into the daily life of almost everyone, that there will probably be few to whom the romance of rubber entirely fails to make an appeal.

The science and practice of rubber planting are alike in their infancy, and in the immediate future important developments are to be anticipated both in our scientific knowledge of the physiological processes underlying the formation of latex, and in the practical methods of exploiting this most valuable of raw materials. It is partly owing to our want of knowledge that it is still possible to compress into a comparatively small compass a summary of what is accurately known of both branches of the subject.

The chapters on the physiology of latex are largely the outcome of original observations by the writer, whilst those on planting, harvesting and factory work on the estate are based on a close personal acquaintance with the industry in Ceylon. The chapter on disease, on the other hand, so far as it relates to the fungus pests of rubber, is little mote than a summary of the work of Mr T. Petch, whose book is indispensable to anyone specially interested in this branch of the subject I am also indebted to Mr Petch for the loan of the illustration of canker on Hevea. Free use has also been made of Mr Herbert Wright's well-known book on Para Rubber, and the student who wishes to enter further into the statistics of rubber cultivation will find therein a large mass of useful information.

Sir Daniel Morris's Cantor Lecturest delivered in 1898, still contain the best and fullest account of the wild sources of rubber, and I have drawn freely upon them for the information given in Chapter II.

The chemistry of rubber has been dealt with only in the barest outline, but the book seemed incomplete without some reference to this side of the subject It is hoped that the brief summary of the processes employed in the manufacture of rubber goods will be of some interest both to the planter and to the general public. Of both these branches an excellent account on a much fuller scale is readily accessible in Dr Schidrowitz's book on Rubber. Other sources of information are acknowledged in a separate list of references.

I am indebted to several friends for advice and criticism. Mr W. N. Tisdall very kindly read through the whole of Chapters v, vi and VII, and made a large number of valuable suggestions, practically all of which have been incorporated. Mr Tisdall also provided the estimate given on p. 127. Professor T. B. Wood was also kind enough to read part of the proofs.

The text illustrations of different rubber-producing species have been drawn for me by Mr L. Denton Sayers mostly from living specimens and I am much indebted to him for the trouble he has taken with them. I have also to thank Mr H. F. Macmillan and Mr C. Northway for the loan of valuable photographs, Mr Staines Manders for the loan of blocks from the Catalogue of the New York Rubber Exhibition, and Messrs F. Shaw and Co. for illustrations of machinery.

I should not forget to mention the name of Mr C. O. Macadam my collaborator in the preparation of the Ceylon Handbook for the Rubber Exhibitions of 1911 and 1912, since this handbook is in a sense the nucleus from which the present volume has been evolved.

Finally it is a pleasure to acknowledge that any literary merit which this volume may possess is largely due to the untiring help and criticism of my wife, who has also devoted great care to the preparation of the index.

R. H. L

1 August 1913.