97 



from the " Journal" of the Society by Messrs. Maclaren & Sons of 

 the "India-Rubber Journal," London. 



The headings of the sections of the lecture will give some idea 

 of its scope ; they are : — Source of Rubber, Botanical Sources of 

 Caoutchouc, Distribution of important Caoutchouc Plants, Rubber 

 Species, Wild Rubber, Distribution of Rubber Plants and the 

 Eastern Industry, Plantation Rubber, Laticiferous and Caoutchouc 

 Plants. 



The last named section, from page 53 to page 71, deals with the 

 following subjects : — Differences between the Laticiferous System 

 of Different Genera — Collecting Latex and Manufacture of Rubber 

 — Methods of Tapping on Eastern Plantations — Systems of Tap- 

 ping in vogue — Frequency of Tapping and Wound Response — 

 Coagulation of the Latex by Acids, Alkalies, Plant Juices, Heat, 

 etc. — Yields of Rubber obtainable— Manihot, Castilloa, Funtumia, 

 and Hevea — Best Yields from Original Cortex — Future Yields 

 from Renewed Cortex — Yields from Young and Old Trees — Ap- 

 proximate Yield per Acre according to distance — Exceptional 

 Yields — Yield according to system — -Latex from different sections 

 of the tree — Noncoaguable Latex from high Parts — Labour and 

 Yields on Small and Large Plantations. 



The information comprised in these 20 pages out of 100 in the 

 book will probably appeal most to the practical planter. 



The lecture gives a good birds-eye view of the whole subject, 

 and should be read by all who are interested in rubber. The 

 planter who has trees ready for tapping will want not only this 

 small book but also Mr. Wright's manual on " Para Rubber." 



GUAYULE RUBBER. 



Considerable interest has of late been attracted to what is 

 known as ' Guayule' rubber in Mexico. The following information 

 in regard to this plant is extracted from an article in Tropenpflanzer, 

 for May 1905 : — 



The 'Guayule' (Parthenium argentatum) is a low perennial com- 

 posite about 2 feet high, with grey bark, silvery leaves, and in- 

 conspicuous yellowish flower heads on long stalks. It is widely 

 spread along the dry calcareous steppes of the northern part of the 

 high plateaux of Mexico, at an elevation of 2,800 to 5,200 feet. 



This plant yields no latex when wounded, but the caoutchouc is 

 in closed cells in the bark and the wood. To extract the rubber 

 the whole plant is dried, ground up, and as much of the woody 

 matter as psssible removed from the small round lumps of rubber 

 which result from the grinding. The rest of the woody matter is 

 then dissolved with hot alkali, and the rubber pressed into large, 

 flat cakes. 



The product contains as much as 10 to 2^ percent, of resins and 

 aromatic substances, and has sold for Is. 5d., to 2s. 4d. per lb. 

 One factory is now working, and four others are planned. It is 



From The Agricultural News, V. 122. 



