EDITORIAL. 
CULTIVATION OF GUAYULE RUBBER. 
A proposal has been brought before the Institute by Mr. W. Ham, of 
_ Adelaide, to introduce into Australia the Mexican plant—Parthenium 
argentatum (A. Gray)—known as the source of Guayule rubber. The 
chief characteristics that recommend its introduction are :— 
The plant lives in very dry soil, with a rainfall less than 10 inches 
a year, and often in rocky ground containing a large percentage of lime. 
Many experiments are being made with it in California and Arizona, 
and experimental manufacturing plants capable of producing annually 
400 tons of purified rubber are in use. 
The plant is of slow growth, but cultivation and hybridization seem 
likely to yield improved strains. Machinery for planting out seedlings, 
cultivating, and harvesting have been devised to reduce the cost of 
manual labour to a minimum. As the whole plant is cut down and 
ground up to obtain the rubber, all the operations can be performed 
mechanically. The amount of dry rubber yielded varies from 7 to 10 
per cent. of the plant weight, and is chiefly contained in the bark. 
__ It was decided to write to the Department of Agriculture at Washing- 
ton for full information on the matter, and for a supply of seeds for 
introduction here. 
SUN-POWER APPARATUS. 
That evergreen subject, “How to convert the sun’s energy into 
mechanical energy,” has again been brought before the Council of the 
Institute of Science and Industry by Mr. F. W. Hiscock, of South Aus- 
tralia. He claims to have invented a sun-power apparatus which will 
focus the heat of the sun on galvanized iron piping containing impure 
water, from which steam of considerable pressure can be obtained, which 
can be either condensed to supply pure water at a total cost of 24d. per 
1,000 gallons, or be converted into power. The Council could not 
support the proposal in. its present form, and costs of an apparatus in 
use in Egypt were supplied by Mr. Leighton, of the Commonwealth 
Arsenal, as 3s. 73d. per 1,000 gallons. It was decided to write to the 
Egyptian Government for full information on their plant and specially 
designed low pressure engine. 
DESTRUCTION OF RABBITS BY DISEASE. 
Another subject that is the cause of much controversy, and also of 
much opposition, is that of controlling the rabbit by the introduction of 
some specific disease. Nothing of a practical nature in this direction 
has been attempted since the investigations of Dr. Danyz on an island 
off the New South Wales coast many years ago. Information has been 
received from Dr. Aragao, of Rio Janeiro (per Dr. Breinl, of Towns- 
ville), about a disease of a very deadly nature that attacks only rabbits 
and hares. All the domestic animals (pig not mentioned), horse, cow, 
sheep, dog, cat, fowl, and pigeon are immune. Dr, Breinl has offered to 
carry out any preliminary tests on caged rabbits. The matter has been 
submitted to Sir Harry Allen, Pathologist, Melbourne University, for a 
report. 
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