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endless experiments, the tests and control tests made to check and | 
confirm the first; the disheartening failures, the apparently 
profitless expenditure of time, money, and eye-sight before there 
can be any tangible result. I cannot perhaps adduce a better 
instance of the actual commercial value of purely chemical and 
theoretical experiments than the recent production of artificial 
alizarin from the waste of coal tar, which was formerly thrown 
away; and was also a great source of pollution to our rivers. 
Aniline and a considerable number of brilliant dyes, of great com- 
mercial value, have, for some time, been prepared from coal tar ; 
and chemists are hopeful that still more may be yet discovered. 
Madder was formerly largely used in dying textile fabrics, and was 
@ more expensive article, but now Dr. Perkins has succeeded in 
producing from coal tar, alizarin, not an imitation or substitute, 
but the identical chemical substance to which madder owes its 
colouring properties. One ton of alizarin does as much dyeing as 
twenty tons of madder. About 3,400 tons are now used annually 
in Great Britain, which cost £457,000, this would represent about 
61,000 tons of madder, which would cost about £2,900,000 ; thus a 
saving of nearly 23 millions sterling has been effected in this 
industry alone by Dr. Perkins having laboriously followed up a 
purely theoretical deduction by experimental research. 
Never yet, perhaps, were inventors better off than in this our 
day, for instead of being looked down upon, as they once were, as 
charlatans or enthusiasts, they are certain of the ready sympathy of 
an educated public ; and aid, in the shape of pecuniary grants, from 
scientific bodies, and perhaps even from a not too enlightened 
government. What is still chiefly exercising the scientific mind is 
the “Germ theory ” of disease—the importance of which can hardly 
be exaggerated, for it bids fair not only to revolutionise medicine, 
but to profoundly modify, in the future, the lves and health of 
unborn generations. Dr. Ferrau’s inoculations tor Cholera have 
hitherto been an undoubted failure, which indeed might have been 
expected from the unscientific (and I might add illiberal) method in 
which they were conducted, nor indeed can Cholera inoculation be 
expected to succeed until it can be proved that one attack is 
preventive of another, which we know is not the fact, Pasteur’s 
more philosophical innoculations with a weakened virus, for the 
prevention or cure of Rabies or Hydrophobia, and Anthrax or 
Malignant Pustule, have had a much larger measure of success, 
- although they must still be considered on their trial. Unfortunately 
three of Pasteur’s patients have recently died of Hydrophobia, after 
haying been inoculated by him with the attenuated lymph, but thie 
failure was perhaps due to their not having been operated on until 
@ month after they were bitten, which was certainly far too long, 
