Another very important product of gas-tar is carbolic acid, which is also largely employed for dyeing purposes. Its value as a disinfectant is too well known to need recapitulation here; but we may mention that its use as a preventive of disease was most abundantly proved during the last epidemic among our cattle. It is in general use in our hospitals, not only as a disinfectant, but also as an antiseptic both in the dressing of wounds and in the treatment of various skin diseases. Carbolic acid also yields a substance called picric acid, which, on account of its explosive properties when combined with potassium, has been proposed as a substitute for gunpowder. There are many other substances derived from the distillation of coal-tar, but at present they are only of interest to the experimental chemist.
A ton of coals will produce a chaldron of coke, twelve gallons of tar, ten gallons of ammoniacal liquor, and nearly ten thousand feet of gas. A consideration of these figures, with a due regard to what we have said as to the value of the various chemical products obtained by distillation, will enable our readers to understand why gas companies can shew such good balance-sheets. Much has been written as to the possible exhaustion, after one or two centuries, of the British coal-fields. This is a question upon which it is next to impossible to form any reliable opinion. Should the coal-supply actually fail, it is more than probable that as science is extended, a new source of light and heat may be developed. A cheap and ready means of producing electricity, as we have in a former article endeavoured to shew, would at once solve the problem, and it is within the bounds of reason that to this agency the future races of the earth will look for the two most common necessaries of existence.
Charles Dickens once wrote to a friend: ‘I have distinguished myself in two respects lately. I took a young lady unknown down to dinner, and talked to her about the Bishop of Durham’s nepotism in the matter of Mr Cheese. I found she was Mrs Cheese. And I expatiated to the member for Marylebone, Lord Fermoy—generally conceiving him to be an Irish member—on the contemptible character of the Marylebone constituency and Marylebone representatives.’ Two such mishaps in one evening were enough to reduce the most brilliant talker to the condition of the three ‘insides’ of the London-bound coach, who beguiled the tedium of the journey from Southampton by discussing the demerits of William Cobbett, until one of the party went so far as to assert that the object of their denunciations was a domestic tyrant, given to beating his wife; when, much to his dismay, the solitary lady passenger, who had hitherto sat a silent listener, remarked: ‘Pardon me, sir; a kinder husband and father never breathed; and I ought to know, for I am William Cobbett’s wife!’