The excise laws have hitherto operated strongly against the establishment of manufactories of muriate of ammonia in England. Hence an immense quantity of sulphate of ammonia obtained from the gas light ammoniacal liquor, is exported from this country to the continent, solely from the extreme rigour of the excise relating to the use of common salt, and it is only this that has hitherto prevented the establishment of manufactories of sal-ammoniac from the ammoniacal liquor of the gas light process upon a large scale.
Chemical manufactories, of all others, will least bear excise, because many of them are worked according to secret processes, which, if made public, must pass into other countries; and the greatest part of the profit ceases together with the export. The vexatious introduction of excise officers into manufacturing laboratories, it is evident, puts an end to all secrecy of operation. There are several chemical processes which interruption will extremely injure, and others which it totally destroys, and as on the whole they in general are of a nature in which interference of others is most peculiarly vexatious, in all probability, if the excise be extended to manufactures of this nature, it will eventually put a stop to most of them, and greatly injure the revenue by causing thereby to cease the duties which at present arise from the exports and imports to a large amount, now depending on the chemical trade of Great Britain.
We have now gone through all the improvements by which the gas light manufacture has been distinguished during the interval which has elapsed since the publication of our former work[65] on this subject; and perhaps the reader may be inclined to think, from the extraordinary height to which improvement has been carried in this art, that little or nothing more remains to be desired with regard to it. Let it be remembered, however, that the whole art is only in its infancy. There is yet a wide field for improvement in the construction of the apparatus. Ingenious men may speculate from what has been done, to what remains to be effected, which no doubt will lead to objects of the greatest utility, and most extended national importance.
Elevation of the Revolving Gas Holder at the Westminster Gas Works 181