292 



THE AGRICULTURAL NEWS. 



Septembee 9, 1916, 



THE HISTORY OF RUBBER. 



In Science Progress for July 1916 appears an interest- 

 ing and instructive article entitled, An Historical Sketch 

 of the Chemistry of Rubber. The first half of this article 

 gives an account of the history and the introduction of 

 rubber into domestic use.s, while the latter half deals 

 essentially with the chemical composition of rubber. 



The first rumours of the existence of rubber are said to 

 have reached Europe after the second voyage of Columbus to 

 the New World in 1193-4. Stories were brought over to the 

 effect that the natives u.sed it to make playing balls, water- 

 proof boots etc. In 17.31, a Fiench expedition led to an 

 exhaustive enquiry into the source and preparation of rubber 

 in Peru and Brazil and an account was communicated to the 

 Academie des Sciences in 17-51. The first chemical study of 

 caoutchouc was published in 1763, but the substance 

 appears to have remained a mere curiosity in Europe, until 

 in 1770 Priestly, the discoverer of oxygen, suggested 

 its use, under the name of India rubber, for erasing 

 lead-pencil marks. And this for many years was the main 

 purpose to which it was devoted. Later the French used 

 a solution of rubber in turpentine for coating balloons 

 but it was not until about 1825 that Macinlo-sh discovered 

 the .solubility of rubber in naphtha, and successfully applied 

 the solution to the fabrication of waterproof garments, from 

 which time the modern rubber industry may be said to 

 have commenced. 



The fact that rubber goods were extremely subject to 

 the influences of the seasons nearly caused a collapse of the 

 whole industry; this however was averted by an American 

 named Goodyear, a chemist of ('onnecticut. After suffering 

 much hardship in prosecuting his research, and even under- 

 going imprisonment for debt, he was rewarded in 1839, by 

 the discovery of the process of vulcanization which overcame 

 influence of seasonal changes and adapted rubber to count- 

 less purposes of mankind. The result was attained by 

 heating the gum with an admixture of sulphur at a high 

 temperature. 



The greatest impetus the rubber industry ever received 

 was undoubtedly given by the reinvention in 1888 of the 

 pneumatic tyre. An air-filled tyre for u.so with carriages had 

 been patented by Thompson in 181-5, but, partly owing to 

 faulty construction, and partly because its advantages at low 

 speeds were not .sufficient to counterbalance the high cost of 

 the large tyres employed, the invention was allowed to droj). 

 The advent of the safety bicycle, with small wheels to which 

 springs could not easily be attached, led Dunlop independ- 

 ently to discover and patent the idea. 



The introduction of rubber tubing proved to be of 

 great benefit in chemical research, since it obviously facili- 

 tated the arrangement of communications between various 

 ve.ssels. Before rubber tubing was u.sed, a lute made of 

 a paste of clay and linseed oil was wrapped around the glass 

 tube connexion. The introduction later of the rubber cork 

 was also of great service in chemical experimental work 



In regard to the chemistry of rubber, it is not our object 

 in this note to deal with the subject at any length. Suffice 

 it to say that caoutchouc is a ])f)lymer of i.soprene from which 

 rubber can be produced synthetically. Isoprene is prepared 

 in large qiuntities from tusel oil. The most dramatic inci- 

 cident in the race between the English and (iorman firms in 

 regard to synthetic rubber was the almost simultaneous 

 discovery of the value of sodium as a polymerizing agent. It 

 was found in both countries that .sodium causes the change 

 to take place quickly, and practically quantitatively, at a low 

 temperature. While possessing the same physical proper- 



ties as synthetic rubbers produced by other methods, the 

 rubbers obtained by the action of sodium appear to have 

 a somewhat different chemical constitution. This, however is 

 of little concern to the manufacturer, providing the material 

 will answer his practical purpose. 



As the result of the researches on synthetic rubber, it is 

 hoped that before long it will be placed on the market. 



REPORT ON THE WORKING OP THE 



ANTIGUA GOVERNMENT GRANARY, 



1915. 



We have received from Dr. H. A. Tempany, Superintend- 

 ent of Agriculture for the Leeward I.slands, a copy of the 

 annual report on the working of the Antigua Granary for 

 191.5. 



I iider the scheme for operating the Government Gran- 

 ary, it was arranged that cob corn should \ e purchased on 

 a co-operative basis, a first payment being made for corn on 

 delivery, while any subsequent profits after paying the cost of 

 working expenses should be divided between the grower and 

 the granary, in the proportion of 75 per cent, to the grower 

 and 25 per cent to the granary. 



It was agreed that the magnitude of the first payment 

 should be based on the current market price for corn, and 

 for the first period of working this was fixed at 6s. Id. per 

 1 1 2 Iti. for corn on the cob delivered at the granary. 



The value was arrived at on the assumption that the 

 corn cob supplied to the granary would yield, on shelling, 

 from 73 per cent, to 75 per cent, grain with a moisture 

 content of 16 per cent. 



Buying operations in this connexion commenced at the 

 end of .July 1915, and terminated in October 1915. Drying 

 proceeded till the end of October, and the whole of the corn 

 had been disposed of by the end of December. 



In all 109,987 Sb. of cob corn were purchased, the 

 expenditure on purcl>ase amounting to £298 18s. \0d. Corn 

 was purchased from fifty-two dffferent growers. 



From the operation 67,032 lb. of kiln-dried corn were 

 obtained the net proceeds from which realized £315 3s. 4(/., 

 or an average of lO.-.-, ()<?. per bag of 112 It). 



The expenditure on working expenses in labour, fuel 

 and materials came to £37 9.s. 9d., while an additional 

 charge of ,£ 1 3 17,<. 10^/. was incurred for bags. This does 

 not include any charge for interest on invested capital, or for 

 rent and insurance. 



It will be .seen that a loss of £35 'is. \d was incurred 

 on the tran.saction, consequently no bonus could be paid. 



The actual shelling percentage of the corn worked out at 

 (55 per cent.; the average moisture content of the corn 

 when purchased was 18-3 per cent.: after drying it was 10 6 

 The actual recovery of kiln-dried grain amounted to 609 p# 

 cent, on the cob corn: this is very small and decidedly bel(W 

 the expected yield. The average moisture cijntent of the 

 corn was also very high and operated in favour (^f the pro- 

 ducer. These two factors are very largely responsible for 

 the result. 



Corn sales extended from September until December, 

 and as no corn was imported into the island during this period 

 until near tlie end of December, it is obvious that the corn 

 sold to the granary represents an overplus of production at 

 the time the corn was reaped which, if the granary had 

 not been in existence, would probably have been subject to 

 considi^rable loss on storage. 



