1 Szpr., 1898.] QUEENSLAND AGRICULTURAL JOURNAL. 213 
Tropical Industries. 
GUTTAPERCHA—ITS HISTORY, 
(From Engineering News, 26th May, 1898.) 
Gurrapencia (says Dr. E. F. A. Obach, in a lecture before the British Society 
of Arts) was first brought to Europe by the Tradescants, in 1656. In 1845 it 
was reintroduced from Singapore, and in 1847 Sir W. J. Hooker gaye it a 
naine, and in the same year EB. W. von Siemens used it for an insulating 
material on a submarine telegraph cable. ‘he original name was Isonandra 
gutta, now altered in England to Dichopsis gutta. The crude commercial 
guttapercha contains from 1-0 to 27 per cent. of water, and from 1:8 to 22°3 
percent, of dirt. The genuine guttapercha has a specific gravity of 09879 at 
15 degrees O. ; begins to soften at 45°7 degrees C. ; is pliable at 65 degrees C. ; 
hardens in $°6 minutes; has a tensile strength of 3,906 1b. per square inch, and 
an elongation of 418 per cent. Its electrical properties per “ cube knot” are: 
Insulation at 75 degrees I’; second min. megohins 5,484; inductive capacity, 
0:0549 microfarads. In England the maximum consumption was 3,000 tons, 
used chiefly for electrical purposes, in 1881-2; by 1896 the consumption had 
fallen off to about 1,200 tons. The various submarine cables in use now 
contain about 24,000 tons of cleaned guttapercha. 
RUBBER CULTIVATION IN AUSTRALIA. 
(From the India Rubber World.) 
Tym South Australian Government has granted a lease of Bathurst Island 
(comprising over 50,000 acres) to Mr. T. Harry, of Adelaide, and a syndicate 
made up from English cycle and rubber firms, acting in connection with some 
colonial (mostly Victorian) capitalists, has been taking steps preparatory to- 
beginning the cultivation of India-rubber on that island on a large scale. I 
have been at some pains, therefore, to investigate this subject for the benefit 
of such India Rubber World readers as may feel interested. 
Bathurst Island, lying sixty miles to the north of Port Darwin, the 
principal port on the northern coast of Australia, is generally flat and in some 
places low. Itis in 11 degrees 19 minutes south latitude. The climate is 
tropical, of course, but visitors to the island assure me that the thermometer 
will not range above 100 degrees F. in the shade on the hottest day, nor much 
below 70 degrees on the coldest. The wet months are from November to 
April, and sometimes May. 
Dr. M. Holtze, F.L.S., now director of the Adelaide Botanical Gardens, 
was for many years curator of the botanic garden at Port Darwin. He formed 
a rubber plantation of a half-acre at the latter place, and reported success with 
both Cear4 and Par& rubbers. He reported favourably upon the soil of 
Bathurst Island, and recommended that the Government plant rubber and 
other economic trees. ; 
The Hon. J. Langdon Parsons, formerly Minister controlling the Northern 
Territory of South “Australia, and Government Resident of said territory, has 
written a confirmation of Dr, Holtze’s report. Writing of a visit to Bathurst 
Island, he said: ‘‘ The soil, when turned up, was a rich vegetable mould, mixed 
with fine sand . . . and, if the land were cleared and cultivated, would 
grow almost any tropical and subtropical plants and trees. I have no hesita- 
tion in saying that any company obtaining control of Bathurst Island can, by 
judicious planting, possess forests of the best Indiarubber trees.” 
