388 I Scientific Intelligence, 6fc. 



lioness litters but once, the plantain bears fruit, and a woman marries 

 but once, (this being the custom of the country), and a brave man 

 never retreats but once, meaning, that he loses his life in doing so. 



On the Geographical Distribution of Plants in lrela>id and 

 the West of Scotland. — Mr. J. T. Mackay read a report which he 

 had drawn up in accordance with a suggestion thrown out by a 

 member of the British Association at its last meeting. 



Caoutchouc. — Mr. Royle in visiting the manufactory of the 

 elastic web from caoutchouc or India-rubber, which is now applied 

 to a variety of purposes, was informed there was a difficulty in 

 obtaining, from South America, a sufficient quantity of caoutchouc, 

 or India-rubber for the purposes of the manufacture, and was, there- 

 fore, led to point out the variety of plants and countries from which 

 the same substances might be obtained. A communication was first 

 read from Mr. Sevier, the sculptor, who has made the principal dis- 

 coveries in the properties of caoutchouc, and the commerce of caout- 

 chouc, by which it appeared, that, since the removal of the duty, the 

 importation of it had increased from 10 to 500 tons annually, and is 

 soon expected to be 2000 or 3000 tons a-year, from its various uses 

 as articles of dress, and ligatures of every kind, as well as for elastic 

 ropes for the breaching of guns, a^d bands for driving machinery. 

 The earliest accounts, by Condamine, Aublet, and Priestley, were 

 alluded to, and the South American tree, yielding caoutchouc, was 

 mentioned under the name Siphonia elastica, that of Penang as 

 Urceola elastica, and the Indian as Ficus elastica, while other 

 plants yield it in Madagascar, Mauritius, Singapore, and China. The 

 natural families of plants, to which all those yielding caoutchouc 

 belong, were stated to be Cichoracece, Loheliacew, Apocynece, 

 Asclepiadece, Euphorbiacece, and Artocarpew, all of which have 

 milky juice, and are in considerable quantities in tropical countries ; 

 there could be but little doubt, that many other plants of these 

 families might be found to contain this useful substance, as well as 

 those which are already known to do so. Besides these general results, 

 it was observed, that many of the plants of this family were remark- 

 able for the tenacity of their fibre, which fitted them for the purposes 

 of rope-making, and that it was singular, that in the attempts to 

 find substitutes for the mulberry-leaf in feeding the silk-worm, so 

 many of the plants, which they prefer, next to the mulberry-leaf, 

 should belong to the families which yield caoutchouc, as the lettuce- 

 leaf, the leaf of Ficus religiosa, the Artocarpece, and the Castor 

 Oil Plant. Considering that these facts were not likely to be 

 accidental, the author was led to infer, that something of the 

 same kind must be contained in the juice of the mulberry, especially, 

 as it belonged to the family of Artocai'pece, and, having requested 

 Mr. Sevier to make the experiment, the author was informed, that 

 he was perfectly correct in his indication, as the mulberry juice also 

 contained caoutchouc, whence it was inferred, that the silk-worm 

 requires some portion of this tenacious substance in its food to enable 

 it to spin its silk, and the fact was communicated, as probably of 

 some practical value, as well as of scientific interest. 



Mr. Hope subsequently remarked, that the dandelion, which had 

 been previously noticed as yiehling caoutch(uic, was one of those 



