254 POPULAR ECONOMIC BOTANY. 



they are of sufficient thickness; the clay is then washed 

 out, and the caoutchouc is ready for market. 



Formerly much was sent from British India; it was the 

 produce of Ficus elastica (Nat. Ord. Horaces) ; but this is 

 found to be so inferior to that produced by the Brazilian 

 India-rubber tree, that it is almost unsaleable in our 

 markets. 



This remarkable vegetable production was first introduced 

 in the eighteenth century. When it was introduced as a 

 curiosity from America, it was in the form of bottles, birds, 

 etc., and excited considerable attention in consequence of 

 its elasticity and inflammability. At first it was used almost 

 solely for rubbing out black-lead pencil marks from paper, 

 hence its familiar name. Nothing was known of the plant 

 from which it was produced, or the mode of production, 

 until an astronomical expedition of French academicians 

 went to South America. M. de la Condamine was fortu- 

 nate enough to see the caoutchouc prepared, and forwarded 

 an account of it to the French Academy in 1763. 



When pure, caoutchouc is very different to the article in 

 common use ; instead of black it has a pale yellow colour. 

 It arrives in various forms; the commonest is Bottle India- 

 rubber : this variety is in various forms, as bottles, shoes, 



