A Manual Of Photography

112 GRIFFIN’S SCIENTIFIC CIRCULAR. March, 1852. ECONOMY IN SUGAR-MAKING. 2815 Just published, in crown octavo, illustrated by 20 Woodcuts, price 3s. cloth, or free by post to any of the British West Indian Colonies, 3s. 6d. DIRECTIONS FOR TESTING cane-juice, so as to determine the exact quantity of Quicklime required to temper a given quantity of Cane- Juice with Practical Instructions for Conducting the Process of Clarification. By JOHN SHIER, Esq., LL.D., Agricultural Chemist to the Colony of British Guiana. The Official Report on the Clarification of Cane-Juice, addressed by Dr. Shier to the Governor of British Guiana, has been published in Demerara, but not hitherto in this country. It is now reprinted, to accompany a collection of Chemical Apparatus, which has been prepared on a plan arranged by Dr. Shier, for the use of Planters who may be inclined to adopt his improved process ot Clarification. In order to render the operation of Testing as intelligible as possible to those not well acquainted with Chemical Experiments, Dr. Shier drew up, during his recent visit to England the Practical Directions FOR Testing Cane-Juice, which form the Second Part of this Worte • and, at his desire, there has been added, an illustrated description ot the Apparatus and Materials that are required to carry his method of Testing into operation. The actual beneficial results of the process are stated in the following summary, contained in the Official Report, presented (18th May, 1850,) by Dr. Shier to his Excellency, Governor Barkly :— “ By following this method, I have prepared many specimens of sugar from canes of various sorts, and from many different localities in the colony, these samples have been transmitted to London, Glasgow, and other markets, to be valued and have ranged from three shillings to eight shillings per cwt. above the average price of Demerara muscovado in the market at the time. But this is not all: in consequence of the saving of juice effected by the mode of clarification being such as admitted of substituting subsidence and filtration for skimming, I obtained nearly twenty per cent, more of the juice than would have been got by the process as usually,conducted, and the juice yielded from 1 lb. 4 02. to 1 lb. 10 oz. of muscovado per gallon.” It has been well ascertained in this country, that the beneficial produce of Chemical Works is greatly increased when the details of the manufacturing processes are regulated scientifically ; and, it is but reasonable to expect, that the regulation of Colonial Sugar- Works by scientific processes, would also prove advantageous. But, it will probably surprise the Planter, who is ignorant of Chemical phenomena, to find the performance of so simple and easy a process, as that recommended by Dr. Shier, leading to so important an improvement as an increase of One-fifth in the Produce of Sugar, without any increase in the Expense of Manufacture,—no change being required in the arrangement of the Conners and other apparatus now in use. The result is one that will no doubt excite the attention of all who are interested in the prosperity and profits of Sugar Estates. Cost of the Apparatus and Materials, complete :— 2816.—In a polished mahogany cabinet . . . 4^. 10s. 2817.—In a strong deal cabinet...............................47. N.B.—The size of the Cabinet is 14 cubic foot. Cost of a packing-case lined with tin, to contain the Cabinet, 10s. If not lined with tin, ...................................4s. The next Part of the Scientific Circular will contain a Catalogue of Apparatus useful in Metallurgy, Assaying, and Centigrade Testing. Bradbury & Evans, Printers, Whitefriars.