1918.] The N.Z. Journal of Science and Technology. 127 
Marine Fibre, by D. C. Winterbottom. Bulletin of the Department of 
Chemistry, South Australia, No. 4, 36 pp., 1917. 
Posidonia—an Insulating Material. 
Posidonia is a short, harsh, brittle, reddish-brown fibre, resembling jute, 
containing about 12 per cent, of moisture and 60 per cent, cellulose. It 
is the dead leaf-sheath of the sea flowering-plant (not seaweed) Posidonia 
australis, which through long centuries has been deposited in a matrix of 
sand and shells over many square miles of shallow sea-flats along the coasts 
of Spencer and St. Vincent’s Gulfs. The beds average some 10 ft. deep, and 
as about 400 tons of sand and water have to be dredged up for each ton 
of dry fibre extracted it can be readily understood that its price can never 
approach the £4 per ton which is about the base price of cellulose for the 
paper industry. As, however, there are nearly 5,000,000 tons in sight cap¬ 
able of being profitably sold at £25 per ton (at this price its value surpasses 
that of all the metals recovered from Broken Hill !), South Australia is 
naturally keen on discovering some use for it. It takes dye readily and 
well, is non-conducting, very light, and has practically no stretch ; but the 
short (2 in. to 8 in.) and brittle fibre reduces its value for the textile trade. 
It is an excellent substitute for horse-hair in mattresses and upholstery 
but its heat-insulating properties have so far proved the most profitable 
Experiments have proved that for equal volumes it is as efficient as wool 
and cork, about 25 per cent, superior to pumice, slag wool, hair-felt, or 
asbestos, and much ahead of sawdust as a heat-insulator. As its weight 
when properly packed for this purpose is about 5 lb. per cubic foot and its 
cost about £20 per ton, its economic value is apparent. Further, it does 
not char until a temperature of 350° F. is reached, and combustion does 
not set in under 500° F. 
The writer of this review has used posidonia very successfully for the 
past two years as an insulating-material. It has given excellent satisfac¬ 
tion in refrigeration service when packed to a density of 3J lb. per cubic 
foot, and at this is over 40 per cent, cheaper than any other suitable 
material he has used. Bough tests (by observing the drop in temperature 
of water initially at 180° F. in similar 10 oz. bottles placed in similar tins 
with equal layers of insulating-material between) showed its superiority to 
slag wool, pumice, hair-felt, boiled paper, and various sawdusts. It is very 
light and convenient to handle and cheap to apply, and he believes it the 
best available material for refrigerated vehicles and stores, and for boiler 
and pipe covering, while it should have an extensive field in ordinary 
building work. S. H. J. 
State of Victoria: Report of the Advisory Committee on Brown Coal. 
33 cm. x 21cm., 32 pp. Mines Department, Melbourne, September, 
1917. 
This is the report of a committee appointed by the Government of 
Victoria to investigate and report in regard to the commercial utilization 
of the brown-coal deposits of Victoria, and particularly for the purpose of 
generating electrical energy. 
The committee was called together on the 13th June, 1917, by the 
Minister of Mines, who explained that the Government desired to ascertain 
whether, in the event of the State undertaking the generation and dis¬ 
tribution of electrical energy in bulk for its industrial development, such 
enterprise would be commercially successful. 
