268 EXPERIMENT STATION RECORD. 



wet weather, trees may be safely tapped at short intervals all the year round. 

 Tapping :e a week would give a good average return of rubber. 



The present crude methods of tapping are considered wasteful and should be 

 replaced by an approved method, using proper tools and implements. The besl 

 season for tapping the trunk is from July to January, when the tree is in leaf. "Tap- 

 ping the bark deeply, or slashing and scoring it obliquely to swell a central stream, 

 fails to produce the best flow of latex, while it undoubtedly injures the tree, but 

 when punctured and scored to the depth of \ in. in the early morning the flow is 

 usually well sustained for a couple of hours." 



The gutta-percha and rubber of the Philippine Islands, P. L. Sherman, Jr. 

 {Philippine Dept. Int., Bureau God. Lab. [Pw6.], 1903, No. 7. pp. 48, pis. 41, maps 

 2).— A study is given of the gutta-percha and rubber industries of the Philippine 

 Islands based upon investigations carried on under the direction of the Bureaus of 

 Forestry and of Government Laboratories, a preliminary report of which was made 

 in the Report of the Forestry Bureau for 1902 (E. S. R., 14, p. 1079). 



The trees producing gutta-percha are said to be among the largest and most strik- 

 ing of the forest trees of the islands. The author recognized 10 species', 9 of which 

 belong to the genus Palaquium and one to Payena. The geographical distribution 

 and characteristics of the different trees are given, after which the author describes 

 methods of collecting and marketing their product. The physical and chemical 

 properties of various samples of gutta-percha are shown and notes given on the prop- 

 agation of the trees. The results of investigation on the propagation of the trees and 

 scientific methods of collecting as worked out in Java and elsewdiere are given. 



The rubber-producing plants of the Philippines are all vines, no true rubber trees 

 being thus far recognized as indigenous to the islands. Two species of vines are said 

 to be well distributed, Parameria philippinensis and an undetermined species, both 

 yielding a good grade of rubber. The methods of collecting rubber are described 

 and the Philippines are discussed as a rubber-producing country through the utili- 

 zation of natural supplies and through the introduction of foreign species. 



Gutta-percha and rubber, P. L. Sherman, Jr., (Philippine Com. Rpt. 1903, pt.2, 

 pp. 393-411, pis. 41, maps 2 ).— This article is essentially a reprint of Bulletin No. 7 of 

 the Department of Interior, Bureau of Government Laboratories, noted above. 



Result of trial with patent palm nut cracking machine (Rpt. Bot. and Agr. 

 Dept. {Gold Coast], 1903, pp. 7, 8).— An account is given of tests of a machine lately 

 placed on the market for cracking the palm nut. With the assistance of the machine 

 a hundredweight of kernels was prepared for 7 shillings, while the same amount 

 cracked by hand cost 12 shillings. About 19 per cent of the nuts passed through the 

 machine unbroken. 



The action of ether vapor in forcing plants, J. Lochot (Rev. Llort. [Paris], 

 76 (1904), No. 11, pp. 250-252, jig. 1). — From a number of trials in the use of ether 

 vapor for forcing plants, the author draws the following conclusions: The action of 

 ether varies according to whether the shrubs to be forced have entered a state of 

 winter repose or not. In the first case etherization will advance the flowering period 

 only a few days, while the blossoms will be of equal luxuriance. In the latter case 

 the period of blossoming is hastened a half and the flowering is much more perfect. 

 In a dry atmosphere at 15° C. from 100 to 150 gin. of ether per cubic meter may be 

 employed without danger, and in a humid atmosphere 300 gm. may be used. The 

 duration of the etherization should correspond to the time necessary for the total 

 evaporation of the ether. In a dry atmosphere 24 hours is sufficient, while in a 

 humid atmosphere 36 to 48 hours are sometimes necessary. In a dry atmosphere 

 the temperature ought not to exceed 15 to 18° C, while in a humid atmosphere it 

 may reach 22 to 25° C. without danger. The most striking results have been 

 obtained in the forcing of lilacs. The differences in favor of etherization with snow- 

 balls ( Viburnum opulus sterilis), Azalea mollis, and Deutzia gracilis were less notice- 



