EXHIBITION, BRITISH INDUSTRIAL. 



419 



resented chiefly by fire bricks and retorts for 

 various purposes. 



Building stones were exhibited in great va- 

 riety. 



Slate was shown in plain slabs, roofing forms, 

 and decorated, that is, enamelled. The Llan- 

 gollen Slab and Slate Company exhibited slabs 

 of great size and good quality, 16 feet and 20 

 feet in length. The Rhhvbryfdir Slate Com- 

 pany showed that a block (18 inches by 10 

 inches) which is an inch and a half thick, may 

 be split and dressed into 39 slates; and that out 

 of a block (20 inches by 10 inches) half an inch 

 thick, 8 slates can be sawn, the waste in such 

 case being hardly perceptible. A model of a 

 slate-dressing machine, consisting of knife- 

 edges placed obliquely on a revolving drum, 

 so as to work like the down-cut of a carpen- 

 ter's saw, was exhibited by one of the Port- 

 Madoc contributors, Mr. J. "W. Greaves; and 

 the company there, above named, seem to have 

 a machine that will dress 12,000 to 15,000 slates 

 per diem, accurately and completely. 



M. Alibert exhibited in the Russian portion 

 of the nave blocks of graphite or plumbago, 

 from an extensive bed Recently discovered in 

 Siberia. It takes so high a polish as to be mis- 

 taken for steel. . In travelling through Eastern 

 Siberia M. Alibert found some traces of this 

 mineral in a remarkably pure state, and know- 

 ing its value and importance, he set himself to 

 work to search for the vein, which he felt satis- 

 fied must be in the neighborhood. For fifteen 

 years, at considerable expense, he persevered, 

 and was at last rewarded by arriving at a bed 

 of graphite. 



The French geological maps of France were 

 numerous and important. Among the more 

 remarkable was an atlas of twelve sheets, form- 

 ing a map of the ancient principality of Dombes 

 in the department of the Ain, a curious district 

 of about 100,000 hectares, of which area more 

 than one sixth has been converted into fish- 

 ponds, which are in number about 1,600, and 

 are emptied every two years to obtain the fish, 

 and to be planted for cereals, and afterward 

 again filled with water and stocked with young 

 fish. The insufficiency of the population and 

 other causes led to the method of cultivation. 

 The method has, however, been most injurious 

 to health in the district. An instalment was 

 shown of a great work, that of ascertaining the 

 levels of principal spots over the whole of 

 France continental, suggested in 1857, by Mr. 

 Bourdaloue, who had already completed a 

 similar work for the department of the Cher. 

 The object is to render more easy and certain 

 the operations having relations to new routes, 

 watercourses, drainage, and irrigation. Great 

 detail and exactness therefore were required, 

 which would involve much expense. The first 

 part of the undertaking, comprising the fixing 

 the principal points, was commenced at the 

 end of September, 1857, and will be finished 

 before the end of the present year. 



CHEMICAL SUBSTANCES AND PHARMACEUTICAL 



PROCESSES. The display of chemicals in the 

 Exhibition was the finest yet collected together. 

 Not only were the exhibitors more numerous 

 than in 1851, but there were more first-class 

 names on the list, hardly one manufacturer of 

 eminence being absent. In the leading branches 

 of chemical manufactures the show was won- 

 derfully good. The specimens of alkalies, alum, 

 and the coal tar dyes generally, constituted the 

 great'bulk of the Exhibition. 



One of the great features in the class was the 

 splendid collection of drugs formed by the 

 Pharmaceutical Society, which filled one of the 

 finest cases in the whole building. 



A new product, for the first time, was ex- 

 hibited the silicate of alumina a beautiful 

 crystalline substance resembling glass. It is 

 formed by mixing two alkaline solutions of 

 silica and alumina ; from the great affinity of 

 the alumina for the silica a union is formed be- 

 tween them of a most permanent character. 

 The bases in the mixed solutions, however, 

 showing a most energetic action in strong solu- 

 tions, when diluted with water have that ac- 

 tion so retarded that they remain in the form 

 of a liquid for some hours, admitting of many 

 useful applications, such as the preserving of 

 stone by induration, and the manufacture of 

 artificial stones, which processes were exempli- 

 fied. 



White wine vinegar is obtained, in the form 

 of acetic acid, from the smaller branches of the 

 oak and other hard woods, and it is now also 

 obtained from sawdust. This dust now finds 

 itself entering the mouth of a long retort 

 through a hopper, is coaxed forward by an end- 

 less screw occupying the whole diameter of the 

 retort, and brought under a heat that implies 

 destructive distillation, thus parting with its 

 volatile products. 



Cundy, of Battersea, exhibited the perman- 

 ganate of potash, a most powerful and innocu- 

 ous deodorizer and disinfectant : its oxidizing 

 powers are beautifully shown by treating pure 

 and impure water ; with a small quantity of 

 the fluid, each water may be perfectly pellucid 

 or clear ; but if organic matter be in solution, 

 it will instantaneously be oxidized and precipi- 

 tated as a powder to the bottom, leaving the 

 water colorless ; but if nothing of the kind ex- 

 ists in the water, it remains tinged with the 

 pink color of the fluid. 



Paraffine was well illustrated. In the Great 

 Exhibition of 1851 Mr. James Young exhibited 

 specimens of paraffine and paraffine oil, and one 

 candle, the product of the distillation of coal. 

 Mr. Young has been fortunate enough to make 

 what Liebig some years ago said would be one 

 of the greatest discoveries of the age viz., the 

 condensation of coal gas into a white, hard, 

 dry, solid, colorless, odorless substance, port- 

 able, and capable of being placed upon a can- 

 dlestick or burnt on a lamp. 



Among the substances shown was a new 

 material, called "Parksine," from the name of 

 its discoverer the product of a mixture of 



