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THE POPULAR SCIENCE MONTHLY 



principal constituent of india rubber, 

 is based on a cluster of at least 10 or 

 20 molecules of the formula C 5 H N . It 

 Thus possesses the same composition as 

 oil of terpentine and other terpenes, 

 which are the chief components of fusel 

 oils. There is a hydrocarbon called iso- 

 prene which has the formula of C 5 H 8 , 

 and it has for some years been known 

 that when this volatile liquid is allowed 

 to stand for some time in a closed 

 bottle, it gradually passes into a sub- 

 stance having the principal properties 

 of natural caoutchouc. The same 

 change may be effected, as Professor 

 Harries had shown, in an article pub- 

 lished last year, by treatment with 

 metallic sodium. Dr. Matthews inde- 

 pendently made the same discovery. 

 The difficulty was that isoprene is diffi- 

 cult to obtain and is more expensive 

 than india rubber. Professor Fern- 

 bach, however, after eighteen months 

 of research, discovered a fermentation 

 process for the production of fusel oil, 

 one of the raw materials of isoprene, 

 from any starchy material, such that 

 the cost will not exceed $150 a ton. 



As is well known, the existence of 

 india rubber was learned from the 

 Indian tribes of South America, and 

 the best rubber known, para rubber, ; 

 still comes from Brazil. In recent 

 years plantations of rubber trees have 

 been set out, especially in Ceylon, and 

 about 300 tons of rubber are produced 

 annually as compared with 70,000 tons 

 from the wild trees. The enormous in- 

 crease in the commercial demand for 

 rubber, due to many causes but first to 

 electrical insulation and later to the 

 introduction of automobiles, has made 

 the natural supply inadequate and 

 greatly increased the cost. It may be 

 confidently expected that the demand 

 will further increase in the future and 

 that rubber could be used to advantage 

 for many purposes if it could be ob- 

 tained at less expense. The discovery 

 of the possibility of artificial rubber at 

 a cost that competes with natural rub- 



ber is consequently an important appli- 

 cation of modern science. 



SCIENTIFIC ITEMS 

 We regret to record the death of Dr. 

 Shadworth H. Hodgson, the British 

 philosophical author; of Dr. Ferdinand 

 Zirkel, emeritus professor of mineral- 

 ogy at Leipzig; of M. F. Lecoq du 

 Bois-Baudran, the French chemist who 

 discovered gallium; and of M. C. 

 Andre, director of the Lyons Ob- 

 servatory. 



A memorial service in honor of 

 Bobert Koch was recently held in a 

 temple dedicated to him, which has been 

 erected at Tokyo. The temple owes its 

 origin to the interest of Professor 

 Kitasato.— Lady Hooker will be grate- 

 ful if any who possess letters written 

 by her late husband, Sir Joseph Hooker, 

 will lend them to her for the purposes 

 of a biography which Messrs. Smith, 

 Elder and Co. will publish. 



The nineteenth International Con- 

 gress of Americanists to be held in 1914 

 will consist of two sessions: the first in 

 Washington, D.. C, and the second at 

 La Paz, Bolivia.— The International 

 Geological Congress will hold its 

 twelfth meeting in Canada during the 

 summer of 1913. It is proposed to hold 

 the meeting in Toronto beginning on or 

 about the twenty-first day of August. 

 —The program for the meeting of the 

 British Association at Dundee on Sep- 

 tember -4 and following days includes 

 garden parties at Glamis Castle, Kin- 

 fauns Castle, Rossie Priory and Cam- 

 perdown and excursions to St. Andrews, 

 Dunfermline, Arbroath and Aviemoie. 

 The president, Dr. Schiifer, of Edin- 

 burgh University, will devote his ad- 

 dress to the developments that have 

 taken place during the last fifty years 

 through the study of the tissues of the 

 body by means of the microscope. Pro- 

 fessor Bragg will discourse on ' ' Radia- 

 tions, Old and New," and Professor 

 Keith on ' ' The Antiquity of Man. ' ' 



