PRESIDENT S ADDRESS — SECTION B. 
55 
Schroder’s modification of Lowenthal’s process of tan-analysis. But 
I would caution my hearers that the results, although strictly compar- 
able if carefully obtained, do not represent gravimetric percentages of 
the bark. Other peremptory claims on my time have prevented me 
determining the constants which, if multiplied by the ordinary results 
obtained when gallo-taunic acid is used in LoweuthaPs process, will 
give results which are strict gravimetric percentages of the particular 
group of barks under examination. 
The matter of selling wattle-bark by assay is a reform. I have long 
advocated, and I intend to persist in the agitation. Buyers and sellers 
know perfectly well that with most lots they buy and sell in the dark. 
One confident buyer often brings the other buyers to bid after him 
like a flock of sheep. They have a few empirical rules, of which one 
is that southern bark is far superior to northern. 80 it is as a general 
rule, but I have seen this rule pushed to such an ignorant extreme 
that the same price has been given for a southern bark as for a 
northern bark of two and a-half times its assay value. Tet if a man 
tried to sell ores of gold or silver except on assay we should think him 
a lunatic. The time will come when anyone who attempts to sell at 
auction bark without assay will be placed in the same category. 
Chemists should unite as one man to secure the reform, and if they 
are prepared to make prompt and accurate analyses the reform will 
come speedily. I suppose, howeA^er, that in no branch of colonial 
commercial analysis have bogus analyses done more harm to the 
honourable profession of chemists than in regard to tans. To my 
knowledge some selling and buying brokers have ceased calling in the 
aid of the chemist because of the discordant results obtained with the 
same piece of bark. 1 have been asked scores of times for an accurate 
method of tannin determination which would enable buyers to run 
over samples rapidly in the salerooms. I know of no more rapid 
method than that of Lowenthal, and when those interested in the bark 
trade are really in earnest there will be no difficulty in exhibiting 
samples in time for buyers to make the necessary analyses. 
There is another matter, of even equal importance, to Avhich I 
would invite the attention of chemists. What is the sense of convey- 
ing, thousands of miles, large and varying percentages of unnecessary 
cellulose ? The foreign tanner wants tannin ; he has no use for the 
ligneous matter. The potentialities of wattle-bark extracts (I lose 
sight of other barks for the moment) are enormous, and what are the 
difficulties P Surely, to tho practical chemist determined to surmount 
them, by no means insuperable! The raw material, including the 
small pieces now wasted, can be digested in wooden vats, the heat of 
the sun assisting in the evaporation in most parts of the colony. But 
we have the wood of the trees themselves, and the exhausted “trash ” 
for fuel, while the evaporation can be pushed as far as expedient in 
vacuum pans, which, owing to the vicissitudes of the sugar industry, 
can now be obtained at a low rate. The key to the difficulty of getting 
rid of the superfluous gum in extracts lies, in my opinion, in the 
judicious use of alcohol, which can be re- condensed and largely saved. 
Arrangements might be made, if necessary, for constituting each 
extract works a bond, and using duty-free spirit. The saving of 
freight by the use of extracts would be very great indeed ; the 
extracts themselves are of fairly uniform composition, while we should 
