May, 1910.] 



399 



Saps and Exudations. 



the idea that there is to be a certain 

 market for the product. The speaker 

 had no hesitation in saying that rubber 

 can be grown that will give a reasonable 

 price, provided it is brought to the 

 market in a standard form. 



He spoke of his recent visit to the main- 

 land, and the fact that in many instances 

 where he registered at a hotel, rubber 

 men came to him and asked if rubber 

 was being produced in Hawaii. They 

 wanted to know how much they could 

 get here. He believed that cotton could 

 be grown as a by-product with rubber, 

 but did not recommend tobacco, as the 

 latter depleted the soil too much and 

 would therefore have a bad effect on the 

 rubber trees. 



Mr. P. T. P. Waterhouse now gave an 

 instructive address on the methods of 

 tapping rubber trees as practised in the 

 Straits Settlements, from which he has 

 recently returned. Mr. Waterhouse re- 

 ported that a great advance had been 

 made in this department of production, 

 since his visit to the rubber plantations 

 there a year ago. Whereas on the 

 former occasion many different methods 

 were in operation and various tools were 

 in use, now a general standard of pro- 

 cedure is observed. The coolies, who are 

 employed for tapping have become more 

 expert and better results are obtained. 

 Owing to the increasing demand for 

 rubber the trees are tapped at an earlier 

 age. Disc harrows are being used in 

 Java to cultivate between the rows of 

 trees, and much benefit is derived from 

 this operation. 



Speaking of the pests of rubber trees, 

 jlr. E. M. Bhrhorn, Superintendent of 

 Entomology, cited the shot-hole fungus 

 and the blight which disfigures the 

 banyan trees. Por these enemies he 

 recommended an application of Bordeaux 

 wash before the trees had attained too 

 great a height. 



occasionally. A description is further 

 given of the way in which this property 

 was discovered. It appears that, during 

 a surveying expedition in Natal, it was 

 noticed that, wheu Euphorbia plants 

 were cut by the clearing knives, the 

 juice formed a layer on them which 

 could only be removed with great 

 difficulty. Further experiments with 

 pieces of iron that had come into contact 

 with the juice showed that these did 

 not rust, and that when they were im- 

 mersed in sea water, at Durban, they 

 remained free from brancles and were 

 not affected by any form of marine 

 life. In Natal, laths coated with 

 Euphorbia latex, together with those 

 which had not been so treated, were 

 thrust into nests of the white ant (Termes 

 bellicscufi) ; after twenty-four hours, 

 the treated laths were found to be un- 

 affected, while those which had not 

 come into contact with the juice were 

 completely riddled by the insect. It is 

 further stated that timber coated with 

 Euphorbia latex remained untouched by 

 the sea worm, Teredo naval is, and 

 mention is made of the employment of 

 the juice in making paint. 



Since this, according to the Agri- 

 cultural Journal of the Cape of Good 

 Hope, as a result of enquiries ou the 

 part of the Somerset East Chamber of 

 Commerce, it has been ascertained that 

 the above statements regarding the pre- 

 serving properties of the juice are 

 correct, and that, although owing to its 

 gummy nature it is no longer used in 

 paints, it is employed by makers of com- 

 positions for ships' bottoms, and an 

 attempt is being made to create an 

 export trade In the article from Cape 

 Colony, 



EUPHORBIA LATEX POR PRE- 

 VENTING CORROSION, 



(Prom the Agricultural News, Vol. IX., 

 No. 203, February 5, 1910.) 



In Newman's Metallic StrucUires an 

 account is given of the use of the milky 

 juice of the Euphorbias (spurges) for 

 preventing corrosion. It is stated that 

 it is only in comparatively recent 

 years that the preserving qualities of 

 Euphorbia latex have been made use of 

 in engineering structures, and then only 



