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BRITISH ASSOCIATION, MEETING AT EXETER. 285 
Artificial Substitute for Madder. 
A large part of the calicoes which are produced in this country in 
such enormous quantities are sent out into the market in the printed 
form. Although other substances are employed, the place which madder 
occupies among dye-stuffs with the calico-printer is compared by Mr. 
Schunck to that which iron occupies among metals with the engineer. 
It appears from the public returns that upwards of 10,000 tons of 
madder are imported annually into the United Kingdom. The colours 
which madder yields to mordanted cloth are due to two substances, 
alizarine and purpurine, derived from the root. Of these, alizarine is 
deemed the more important, as producing faster colours, and yielding 
finer violets. In studying the transformations of alizarine under the 
action of chemical reagents, MM. Graebe and Liebermann were led to 
connect it with anthracene, one of the coal-tar series of bodies, and to 
devise a mode of forming it artificially. The discovery is still too re- 
cent to allow us to judge of the cost with which it can be obtained by 
artificial formation, which must decide the question of its commercial 
employment. But assuming it to be thus obtained at a sufficiently 
cheap rate, what a remarkable example does the discovery afford of the 
way in which the philosopher quietly working in his laboratory may 
obtain’ results which revolutionize the industry of nations! To the 
calico-printer indeed it may make no very important difference whether 
he continues to use madder or replaces it by the artificial substance ; 
but what a sweeping change is made in the madder-growing interest ! 
What hundreds of acres hitherto employed in madder cultivation are 
set free for the production of human food or of some other substance 
useful to man! Such changes can hardly be made without temporary 
inconvenience to those who are interested in the branches of industry 
affected; but we must not on that account attempt to stay the progress 
of discovery, which is conducive to the general weal. 
A New Opium Base. 
Another example of the way in which practical applications unex- 
pectedly turn up when science is pursued for its own sake, is afforded 
a result recently obtained by Dr. Matthiessen, in his investigation 
of the constitution of the opium bases. He found that by the action 
of hydrochloric acid on morphia a new base was produced, which, as to 
