234 RErORTS ON THE STATE OV SCIENCE. 



Hayti played a game with balls made from the gum of a tree, ajid that 

 the balls were lighter and bounced better than the wind balls of 

 Castile. 



Torquemada, in 1615,^ described the tree yielding this gum as one 

 which the Mexican Indians called Ulequahuitl, and although there is 

 much doubt about the point, it has been i-egarded as identical with the 

 tree now known as Castilloa elastica. Torquemada also mentioned that 

 an oil was obtained by the action of heat on the rubber, which was used 

 for various medicinal purposes. The Spaniards, even at this early date, 

 used the juice of the tree to waterproof their cloaks. 



No rubber seems to have reached Europe, however, till a much later 

 date. 



La Condamine, the celebrated French explorer, was the first to give 

 any accurate information regarding rubber trees (about the year 

 1735). In 1751 the subject is again mentioned in the researches of M. 

 Fresnau, published by the French Academy, and M. Aublet, in 1755, 

 described a caoutchouc -yielding tree occurring in French Guiana. Such 

 trees were also described by J. Howison (1798), and later Roxburgh 

 showed that Assam rubber was the product of the tree Ficus elastica. 



Berniard," in 1781, described the processes of the collection and work- 

 ing up of indiarubber, and mentioned the oil which is formed from it by 

 dry distillation. 



Priestley alludes to the use of indiarubber as an erasing material in his 

 work on ' Perspective,' and the oil obtained from indiarubber is again 

 mentioned in Fourcroy's ' Systeme de Connaissances Chimiques,' published 

 in 1790. 



Investigations on the Products of the Destructive Distillation of 



Indiarubber.^ 



In the year 1833 W. H. Barnard,^ in the course of some experiments 

 at the works of Messrs. Enderby, at Greenwich, obsei'ved that when 

 caoutchouc was exposed to a temperature of about 600' F. (315° C.) it 

 was resolved into a vapour, which on cooling condensed to a liquid having 

 remarkable properties, and to which the name caoutchoucine was given. 

 Barnard obtained a patent in August 1833* for this invention 'of a 

 solvent not hitherto used in the arts.' In the specification the process of 

 preparation is indicated, and a diagram is given of the cast-iron still and 

 water-cooled worm condenser used in the distillation. The still was 

 slowly heated until the temperature registered had risen to 315° C, and 

 during this period a dark-looking liquid distilled over, which Barnard 

 claimed as his invention, the liquid being a solvent of caoutchouc and 

 resinous and oleaginous substances. He afterwards rectified this liquid 

 and obtained fractions varying in specific gravity, of which the lightest 

 was not below -670. 



He stated that at each rectification the oil became more bright and 



' Loo. cit. 



" Rozier, OhgervationB et Memoires s^ir la Physiqtie. 



' The iauthor acknowledges his indebtedness to the concise collection of the 

 literature on this subject, published by Dr. R. Ditmar, Graz, in the Gumvii Zeitiing, 

 1904. .^ . . y. 



* Dr. Ure's Dictionary of Arts, kc, 1853, p. 358. 



* Specification No. 6466, August 20, 1833. 



