A review of the fluetuatione in the aupplica during the past 5 years ehowe the following facto. Holland aent ue 2651 cwt. in 1876, 1059 in 1878, and 1576 in 1880. Portugal : 3329 in 1877, 2285 in 1879, 3871 in 1880. Portuguese W. Africa : 3881 in 1877, 1822 in 1878, 5248 iu 1880. Portu guese E. Africa : 617 in 1876, 131 in 1877, 1497 in 1880. Fernando Po : 241 in 1876, 52 in 1877, 277 in 1878, 117 in 1879, 248 in 1880. W. Coast Afri-a : 16,841 in 1876, 9632 in Isis, 17,426 in 1880. E. Africa (native etates): 1263 in 1876, 7855 in 1880. Madagascar: 32 in 1876, 83 in 1877, nil in 1878, 110 in 1879, 501 in 1880. Borneo : 15 in 1876, none since direct. Central America ; 5425 in 1876, gradually falling to 2440 in 1880. Mexico: 62 in 1876, 291 in 1878, 50 in 1880. New Granada (Colombia): 3398 in 1876, gradually falling to 1024 in 1880. Venezuela : 521 in 1876, 354 in 1877, 710 in 1878, 482 in 1879, 986 in lss0. Brazil: 80,828 in 1876, 90,917 in 1878, 76,466 in 1880. Gambia and Sierra Le:me: 2827 in 1876, 5641 in 1877, 3808 in 1879, 7104 iu 1880. Gold Coaet : 585 in 1876, 12 in 1879, 167 in 1880. Cape : 774 in 1876, 2120 in 1877, 1431 in 1878, 4620 in 1880. Aden : 2494 in 1876, 1254 in 1878, 6720 in 1880. Mauritina: 1790 in 1876, 570 in 1879, 1550 in 1880. Beng,a1 and Burma : 12,990 in 1876, 9260 in 1878, 10,261 in 1880. Straits Settlements: 7615 in 1876, 5436 in 1s78, 11,582 in 1880.
The exporte of Bornean rubbere are included under guttapercha (pp. 1653-4). Of Brazilian ports, Ceara, in 1878, sent 40,377 kilo. to England, 258 to Hamburg, and 74 to Havre. Panama (in Colombia) aent 23,128/. worth of rubber to the United Statee in 1879. Coata Rica exported 27,854 lb. of rubber in the yeox ending Apr. 30, 1879 ; the quantitiee in previous years had been 57,213 in 1875, 59,427 in 1876, 90,576 in 1877, 78,231 in 1878 ; the shipments from the port of San Jos6 in 1880 were tone, 2078/. Ecuador exported 7059 quintals, value 24,7071., in 1877 ; 6561 quintals, 22,963/., in 1878 (of which, 5853 went to the United State°, and 708 to England); 5394 quintals, 33,564/., in 1879; 7995 quintals, 59,972/., in 1880 ; in 1873, the exports were 16,365 quintals. Guatemala, in 1879, exported 1873 lb. to Belize; the value was 262 dol.; in 1877, the value was 2723 dol. The exporta from British India were 15,893 cwt., 108,645/., in 1875 ; 15,258 owt., 97,861/., in 1876; 13,308 cwt., 90,1691., in 1877 ; 13,794 cwt., 89,381/., in 1878 ; 10,033 cwt., 61,6851., in 1879. The exporte from the Lakhimpur district in 1871 were 260 tons, value 8340/. Assam exported 11,000 maunds (of 82 lb.) in 1873, and Sikkim 700. The exporte from Java were 704 picula (of 135f lb.) for the 1876 crop ; 15 to Holland and 10 to Singapore for tbe 1877 crop ; 47 to Holland aud 15 to Singapore for the 1878 crop ; 135 to Holland and 58 to Singapore for tbe 1879 crop. The valuee of exporte of rubber from Madagascar to Mauritius have been 37,458/.
in 1873, 21,452/. in 1874, 14,539/. in 1875, 9770/. in 1876, 4672/. in 1877. The Venezuelan exporte were 2545 lb. in Britieh veesels, and 53,403 lb. in American, in 1878; and 27,563 lb. in American vessels in 1879. Mozambique exported 443/. worth in 1873, 22,198/. in 1876, and over 50,000/. in 1879 ; the figures have now probably reached their maximum, until roads shall have been made into the interior.
Values.-The approximate relative market values of the principal commercial rubbera entering London are as follows :—Paza, fine, 2-3s. a lb. ; negrohead, ls. 6d.-2s. 6d. Central American, ls. 6d.-2s. 6d. Assam and Pegu, 9d.-2s. 6d. Other E. Indian, is.-2s. 6d, Madagascar and Mozambique, ls. 3d.-2s. 8d.
Suggested Improvements in Collecting and Preparing Rubbers.—The time of year at which the sap ascends to the flowers has an effect on the quantity of rubber yielded. Too frequent tapping causes each successive yield to be less rich in rubber and more watery, and permanently injures the trees. Judicious tapping has no ill result. As to the manner in which the tapping should be performed, this will vary somewhat according to circumstances. Some remarks on tapping and barking other kinds of tree will be found under cinchona (see Drugs, p. 803), manna (sec Drugs, p. 817), and maple-sugar (see Sugar); also under Copaiba, Gurjun, Peru, Tolu, Turpentines, and Varnishes, in the present article. The Brazilian plan of a perpendicular incision, with oblique tributary cuts on each side, has much to recommend it. Paring the bark, after the Ceara method, might also be advisable. The one great object to be kept in view is the avoidance of injury to the cambium layer. This is best effected by using an implement which is so made that it can only just remove or penetrate the bark sufficiently deep to reach the laticiferous vessels, residing mostly in the mesophlceum or middle layer of the bark. A modification of the knife used in marking standing timber, with the addition of a shoulder to adjust the amount of penetration, and a long handle, would probably meet all requirements. A clean cut, as opposed to a ra,gged one, not only heals readily, but keeps the product free from woody impurity.
The collected milk should be coagulated as rapidly as possible, for decomposition soon sets in, and materially modifies the character of the article. Some of the milks keep much longer than others without undergoing great change, but the collection of the day would always be best dealt with during the same day. It is undoubted that an effectual evaporative process for removing the water will produce a better article than any of the saline solution methods. A convenient form for the prepared rubber is thin (1-2 in.) sheets, which are easily packed into bales, and enable the amount of impurity to be readily arrived at.