V 



SCIENTIFIC NOTICES. 25 



or the surface of a mass being made fresh, by cutting, the prop- 

 erties of adhesiveness and solubihty are fully demonstrated. 

 The French and English, in their first experiments, seeipfied to 

 understand, better than the Americans, the true nature of the 

 gum ; they proceeded, at least, with more caution, and confined 

 themselves to the safe and successful applications to which it 

 was adapted at that time, as will appear in the chapter upon 

 •' Foreign Manufacture." 



The following extracts from scientific works may be interest- 

 ins to the reader : 



From the Penny Cyclopedia, 1836. 



Caoutchouc. " This remarkable substance is produced by 

 many different plants. That which comes from the tropical 

 parts of South America is obtained from Siphonia (or Hevea) 

 elastica ; and most other euphorbiaceous plants furnish it more 

 or less abundantly. Various Urticaceae yield it, especially Ficus 

 elastica, and the rest of the genera of the Artocarpeus sections ; 

 Cecropia pellata has even been asserted to furnish a large pro- 

 portion of the American caoutchouc, but this is doubted by 

 Humboldt, because its juice is difficult to inspissate. In Papautla 

 it is yielded by a plant called Ule, which the Berlin botanists 

 call Castilloa elastica. Several Apocynaceous plants secrete 

 this matter, as Urceola elastica, in Sumatra; a species of Na- 

 hea in Madagascar ; and Willughbeia edulis, in India, but the 

 latter is of a bad quality. Among Asclepiadaceous plants, Cy- 

 nanchum ovalifolium is asserted, by Wallich to afford excellent 

 caoutchouc at Penang." 



" In South America the natives have long made water-proof 

 boots of caoutchouc, and by imbruing cloth with the milky juice 

 of the hevea have rendered it impervious to moisture." 



?3^o- 



