352 



SCIENCE. 



[Vol. V., No. 116. 



view that must be essentially imaginary, — a method 

 of illustration that is unfortunately too common in 

 works on geography. 



— As the result of a series of observations made at 

 seventeen forest meteorological stations in Prussia, 

 Professor Miittrich has arrived at certain definite 

 conclusions respecting the influence of the forest on 

 temperature, which may be stated as follows : 1. The 

 forest exercised a positive influence on the tempera- 

 ture of the air; 2. The daily variations of temperature 

 were lessened by the forest, and in summer more than 



given concerning the waste resulting from this pro- 

 cess. By actual experiment, Mr. Wray has found, 

 first, that the wet bark which is now allowed to rot 

 in the jungle contains fully 5.7% of its weight of 

 gutta-percha, or, when dried, 11.4%; and secondly, 

 that, by simply pounding and boiling the bark, nearly 

 all this gum may be extracted. From the trunk of 

 a tree, which he estimated to weigh 530 pounds in a 

 wet state, he obtained but twelve ounces of gutta- 

 percha by the ordinary Malay method, whereas, by 

 boiling, 28 pounds more can be obtained; that is, 



THE CREVASSE NEAR GUEVEJAR, OPENED BY THE EARTHQUAKES IN SPAIN LAST DECEMBER. (From La Nature.) 



in winter ; 3. The influence of the leafy forest was in 

 summer greater than that of the pine-forest, while 

 in winter the tempering influence of the pine-forest 

 preponderated over that of the disfoliaged forest. 

 An attempt to determine the influence of the forest 

 on the mean annual temperature led to no sure re- 

 sults. 



— By the present method of extracting gutta- 

 percha, practised by the native Malayans, the tree is 

 cut down, and the bark slit at various intervals, and, 

 after the gum which exudes is removed, the tree is 

 allowed to rot in the jungles. From a paper by Mr. 

 J. L. Wray, jun., curator of the Perak museum, pub- 

 lished in the Journal of the Straits settlements branch 

 of the Royal Asiatic society, some startling facts are 



for every pound collected, 37 pounds are wasted. It 

 is stated that the export of gutta-percha from the 

 Straits settlements and peninsula in 1875 reached 

 the total weight of 10,000,000 pounds. From this it 

 will be seen that there was no less than 300,000,000 

 pounds actually wasted, which represents £37,500,000 

 sterling. This estimate only includes the trunk, 

 whereas the branches, and even the leaves, contain 

 the gum. Such a wholesale waste of a material so 

 vastly important to the world should be at once 

 prevented if possible; and the question naturally 

 arises, Can the bark be broken from the trees, and 

 dealt with in the country, or can it be dried and 

 sent to Europe to be worked over so as to be a com- 

 mercial success ? 



