Salt and the salt industry

by Albert Frederick Calvert

WITTON BROOK, NORTHWICH. SUBMERGED TRACT OF AGRICULTURAL LAND

Holland combated the general impression obtaining at the time, that salt formed from the same brine varied by the application of different degrees of heat, not only in external appearance but also in quality, and the equally prevalent idea that salt formed from natural brine was inferior in its power of preserving animal flesh to bay-salt. He proved by quotation and experiment that such prejudices were entirely unfounded, and proceeded to show that the action of bay-salt is exactly similar to that of the large-grained salt, and that neither variety has any advantage over the salt prepared by a boiling heat except in the size and compactness of its crystals and in its containing a somewhat smaller proportion of the water of crystallization; and as the large-grained fishery salt is more than equal to the bay salt in these important points, it at least equals the latter in its power of preserving animal flesh or provisions.

The first person who introduced steam heat into the manufacture of salt, and, in so doing, anticipated the revolutionary improvements which were achieved some three-quarters of a century later by the Vacuum System and the Hodgkinson Patent Salt-Making Process, was William Furnival. For our knowledge of the intentions and achievements of this bold and persevering innovator we have to rely almost entirely upon his “Statement of Facts, Humbley and Respectfully submitted to the Consideration of His Majesty, His Majesty’s Ministers, and Both Houses of Parliament.” In this document we have a story of oppression, conspiracy, and persecution which the author describes as “unparalleled in free England,” and since his narration of the treatment he endured has never been refuted, we must conclude that the gist of what he writes is substantially true. It is to be regretted that in this only available account of his activities, Furnival is so intent upon exposing the wrongs to which he had been subjected that he omits to furnish us with a detailed description of his process. We know that in 1823 Furnival erected works at Droitwich and commenced making salt, and we have his assurance that his patent answered every expectation he had formed of it. Moreover, its working was investigated by Messrs. S. Fowler, Fardon & Co., who, on 17th April, 1824, certified that the advantages of the Furnival method over all existing processes, consisted—

“Firstly.—In the saving of fuel which may be stated at about one-half.

“Secondly.—In the production of twice the quantity of salt, as usually made in vessels of the same size, in a given space of time.

“Thirdly.—In the superior quality of the salt, arising out of the regular distribution of heat to the bottom of the brine pan.”

In April, 1825, Furnival disposed of his salt property at Anderton, and three years later, to a month, he bought property at Marston for £1,550. On this ground he erected works covering an area of about twelve acres, and installed some three miles of pannage at a cost of upwards of £135,000, capable of producing some 130,000 tons of salt per annum. He subsequently bought and started to erect works intended, when finished, to occupy nearly six acres of ground at Marston. He asserted that these Wharton and Marston properties were the only two in the kingdom possessing the peculiar advantages of inexhaustible supplies of fully saturated brine and dry rock-salt on the same premises, and he claimed that he could not only deliver rock-salt at fully 25 to 30 per cent. less than any other mine in the country, but, further, that the salt made on his principle was admitted to be superior in quality, owing to the regular distribution of heat, by which more uniform and superior crystals were produced. In the autumn of 1829, he opened negotiations in two separate quarters to lease on royalty certain portions of his salt-works at Wharton, and two committees, each consisting of three men, were appointed by the prospective tenants to investigate the system. On 22nd August, 1829, the two committees drew up a joint report, from which I extract the following—

“The first committee entered upon the investigation on the 15th August, 1829; remained on duty eight hours; was then relieved by the second for the like period, and so continued the investigation, alternately superintending the weighing and delivery of the coals and salt, and taking note of the temperatures every hour.

“The following is the result of working for 162 hours, a steam boiler, constantly fed with brine, the specific gravity from 23 to 25·100ths.