43 
IMPORTANCE OF THE STUDY OF CHEMISTRY. 
the agriculturist in the preparation of most efficient manures,—I should 
have to unfold a picture for which it would be difficult to find the appro¬ 
priate frame. Nor could I omit to show you Leblanc struggling with pre¬ 
judice for the adoption of his great discovery: the transformation by the 
agency of sulphuric acid of sea-salt into carbonate of soda ; or to lead you into 
the busy factories of Lancashire, which now, after the lapse of less than 
half a century, provide not only this country, but half the world, with soda. 
Nor would the picture be complete without the glassworks and the soap 
manufactories in the distance, the operations of which have been forced into 
unprecedented activity by the production of soda, without the bleaching 
yards, which owe their very existence to Leblanc’s great discovery ! 
It would be equally instructive to trace, in brief outlines, the history of 
coal gas, the manufacture of which has become, during the last thirty years, 
of truly national importance. 
The evolution in different localities of inflammable gases from the ground 
has been noticed from time immemorial, and the connexion of these gases 
with deposits of coal had been recognised as early as the middle of the 
seventeenth century.* Years, however, elapsed before correct views of the 
nature of these gases were established by experiment. In 1739, coal was 
for the first time subjected to distillation by Dr, Clayton, Dean of Kildare, 
who thus succeeded in imitating artificially the formation of native gas. 
From this moment the subject was never lost sight of, but it was not till the 
end of the last century that the intellectual impulse of that memorable 
period overcame the difficulties opposed to the practical application of this 
new source of light. These obstacles we know have been at last entirely 
removed, gas light is now universal. Our streets, our public buildings, our 
private dwellings, are brilliant with its radiance. In our daily enjoyments 
of its benefits, we have almost ceased to be conscious of the comfort and 
even personal security, which we owe to this, as yet, the best, cheapest, and 
safest of lights. 
But, to the attainment of this end, how many were the scientific problems 
to be solved, how often had the gas-maker to seek the assistance of the 
scientific chemist, and to avail himself of the results of his researches, in¬ 
stituted originally perhaps for very different purposes ! What a difference 
between the gas with which Mr. Murdoch lighted up the Soho Foundry in 
Birmingham, and that now circulating in the arteries of our nightless towns ! 
The gas produced by the distillation of coal is not an uniform subst ance. 
Together with the principal illuminating constituents, light carbonetted hy¬ 
drogen and olefiant gas, many other gases are evolved during the distillation, 
some of which, e.g. hydrogen, tend rather to diminish the illuminating 
qualities of the gas, whilst others, as ammonia and sulphuretted hydrogen 
are injurious to health. This formed a serious obstacle to the adoption of 
coal-gas as a domestic light. By the aid of chemistry, the composition of 
coal-gas was ascertained, and the nature of its constituents, useful and 
deleterious, determined. Founded on the knowledge thus obtained, means 
were devised for the separation of the latter ; the temperature was indicated, 
at which the purest gas comes over during the process of distillation, whilst 
for the improvement of gas less rich in illuminating constituents, the 
beautiful and economical process of naphthalisation was suggested. And, 
finally, simple and elegant burners were contrived for the safe and economical 
combustion of the product. 
The extent to which the use of gas has affected the arts and manufactures 
in this country can only be conceived by those who are aware of its innumera- 
* Mr. Shirley’s experiments on the burning well of Wigan, in the ‘Trans, 
of the Royal Society’ for 1659. 
