PREFACE TO THE SECOND EDITION. 



IX response to requests made by persons engaged in tropical 

 economic botany and agriculture a second edition of " Hevea 

 Brasiliensis " has been written. 



Advantage has been taken of the short interval between the two 

 editions to collect all the data available regarding the botany, 

 cultivation, chemistry, and diseases of Hevea brasiliensis. The 

 results, which have been obtained during 1905 and 1906 in the 

 Botanic Gardens at Henaratgoda and Peradeniya, on public pro- 

 perties in the Straits, India, and Ceylon, and the observations 

 recorded in the various economic publications in the Tropics and 

 Europe, have been as far as possible included in this issue. 



In arranging the material for this edition frequent reference has 

 been made to Weber's Chemistry of India Rubber, Journal D'Agri- 

 culture Tropicale, Jumelle's Caoutchouc et la Gutta, Revue des 

 Cultures Coloniales, Der Tropenpflanzer, Seeligmann's Le Caout- 

 chouc et la Gutta Percha, Obach's Cantor Lectures, the Annals 

 of Botany, London, Johnson's Para Rubber, the India Rubber 

 Journal, India Rubber World, the Tropical Agriculturist and Maga- 

 zine of the Ceylon Agricultural Society, the Circulars and Annual 

 Reports of the Royal Botanic Gardens, Ceylon, and the Bulletins 

 and Official Journals of the Royal Gardens, Kew, the Imperial 

 Institute, London, the Federated Malay States, and West Indian 

 Departments of Botany and Agriculture. 



The book takes a much wider view of the whole subject, with 

 the object of giving a better understanding to persons not resident, 

 but interested, in the Tropics, and to those directly concerned 

 with the cultivation of the trees, the preparation of rubber, and the 

 manufacture of articles therefrom. It should be clearly understood 

 that the whole industry, especially as far as the producers are con- 

 cerned, is in its infancy, and though our knowledge regarding the 

 function of the latex, the effect of removing cortical tissues and 

 latex from the plant, the methods of extracting latex, yields obtain- 

 able, and the production of rubber from latex, is considerable, one 

 must be prepared to give up present-day ideas and commence 

 work on new lines, whenever the latter have been shown to be 

 worthy of adoption. 



I cannot omit to acknowledge the valuable assistance which 

 Planters and Officials have given me in Ceylon, India, the Straits, 

 and the West Indies, in connection with this edition. 



H. W. 



Peradeniya, May 11. 1WU. 



