. 
SCIENCE AND INDUSTRY. 
to be accepted as a criterion, it was inferior to many Australian leathers. 
An English expert to whom that English sample had been submitted 
at once picked it out as the best leather—that was because he was 
attracted by the colour and the general appearance. It was not, how- 
ever, superior to the bulk of the Australian sole leathers that were then 
being examined. He knew of no satisfactory laboratory test for com- 
paring wearing qualities; he had, however, devised a rough and ready 
test. By attaching leather to a wheel and revolving it so that the leather 
acted as a brake-shoe, some interesting figures of the wearing value 
of sole leathers were obtained. Different samples would take from 
4 to 30 minutes to wear through 1-10th inch. The English soles— 
taking the worst of the Australian soles as 1, were on the average about 
3, while the Australian ranged from 24 to 6. One sample had been 
known to go to 8. The chemical analyses of these were practically 
identical. A firm in Melbourne made the best sole leather, so far as 
he knew, and one sample of theirs under this test went to 8.5. They 
used wattle bark. Attempts he had made to obtain a first-class sole 
leather that was much better than the Australian article had failed, 
and he was by no means certain that the local stuff was so much inferior, 
Mr. Bell said that he knew of no system.of grading in England—or 
anywhere else—but if grading were attempted here it would be 
essential to combine a knowledge of tanning with laboratory tests. Mr. 
Bell said that he had read both Mr. Coombs’ and Mr. Anderson’s 
reports on Australian leathers, and was more inclined to agree with the 
latter than the former. His opinion was that the best leather was not 
turned out in Australia, but that the quality could be greatly improved. 
He thought that Australian leather was susceptible of great improve- 
ment, and that if this improvement were made no better leather would 
be produced. It was generally recognised that a much longer time in 
the pits than was given in Australia would be a great advantage. Until 
that was tried, it was not, perhaps, worth while trying other things. 
Wattle bark should be thoroughly tested. On the test figures previously 
rere ee to the bulk of the Australian leather would be represented 
y 3. 
UTILIZATION OF SPENT WATTLE BARK FOR PAPER MAKING. 
On the outbreak of war the German market for wattle bark was 
closed, and the bark was placed on the English market. The Imperial 
Institute took the opportunity of again urging the British tanners to 
use larger quantities of wattle bark, or in its place, the concentrated 
tannin extracts that were being manufactured both in England and 
Natal. The normal bark contains about 32 per cent. tannin, whereas 
the extracts contain from 60 to 65 per cent. tannin. There was a good 
response to the Institute’s action, and both the bark and the extracts 
found an expanded market. This led to the accumulation of stocks of 
spent bark, and the Institute initiated experiments on the preparation 
of pulp for paper making. These experiments have been successful in 
proving that (1) the dried bark yields 30 per cent. of pulp suitable 
for manufacture into a very good brown wrapping paper, and that (2) 
the wood yields pulp which is of a rather poor strength owing to the 
shortness of the fibre, but when mixed with equal parts of bark pulp. 
makes a satisfactory straw board. ; 
200 
