Class X.] KNIGHT’S CHEMICAL CABINET—GRIFFIN’S GLASS INSTRUMENTS, &c.

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being established by means of wires and cranks in conne.xion with a clock movement.

Brooks (United States , No. 222, p. 1450) exhibits abell telegraph for the use of hotels, &c., consisting of onebell, with a series of springs; it seems well adapted forits work.

Howland (United States , No. 486, p. 1465) hasexhibited a bell telegraph for the use of hotels, dwelling-houses, steam-ships, &c., aud is designed to avoid thecomplication of bells necessarily employed in largeestablishments. Each signal on the dial of the instru-ment is distinct, and remains fixed until relieved byan attendant. It may readily be attached to the usualarrangement for bells. It is ornamental and requires butlittle space.

Chemical Apparatus.

A very small number of manufacturers have contributedto the Exhibition, and, with the exception of Quennessen(Fiance, No. 1683, p. 1257), and Staffed (Russia , No.148, p. 1371), no great preference can be given to one orthe other of the principal Exhibitors. It may, however,be mentioned, that, more or less, the chemical glass andchina apparatus, made by German manufacturers, havebeen exhibited by the majority, which indicates itsadaptation to practical use, as might be expected from itsgreater lightness and durability.

No new invention, except that of Mr. Staffel, nor anynew application of known construction of apparatus, ismentioned.

Knight and Sons (No. 453, pp. 462, 463) exhibit achemical cabinet, containing apparati for laboratories,graduated cylinders, jars, blow-pipes, an improvedbellows, pneumatic troughs, chemical tests; lamps, re-torts, and other glass articles; apparati from iron andearthenware, arranging furnaces, mortars, &c., being acomplete set of articles in daily use by the practicalchemist.

This cabinet is intended to combine usefulness witheconomy: it is proposed that such cabinets should befitted up with apparati and tests for the agriculturist, theanalyst, the commercial man, and the student, with theprices attached to each article, so that the amount of thefirst outlay being under control, the ultimate expensemay be known with certainty, and the difficulty ofselecting appropriate and useful apparatus avoided ; aswell as the necessity of devoting an entire room to thepurpose. This cabinet promises to be highly useful.

A Prize Medal was awarded to Knight and Sons fortheir chemical cabinet.

Knight and Sons also exhibit a chemical furnace onthe same principle as that of Dr. Black, which is con-structed of stout sheet-iron lined with fire-bricks, and isapplicable to nearly every purpose for which a furnace isrequired; one sand-bath, stoppers, crucibles, muffles,rings, &c.

Knight and Sons also exhibit a galvanic battery,according to the arrangement of Daniel!, consisting of aseries of six cells, each holding a copper cylindricalvessel, to be filled with a solution of sulphate of copper,in the centre of which is a porous tube, filled with dilutedsulphuric acid, and containing an amalgamated zinc rod ;also a battery on Grove’s arrangement, consisting of aseries of six cells, each comprising a glass vessel, contain-ing an amalgamated zinc plate, to be filled with dilutedsulphuric acid, having in the centre a flat porous cell,with a platina plate, and filled with nitric acid ; alsoanother battery on Green’s arrangement, consisting of aseries of six cells, each comprising a glass vessel, con-taining diluted sulphuric acid ; to each cell is a series ofthree plates, the centre one being of platinised silverplate, and the others amalgamated zinc. These platesare connected to one rod and can be easily raised out ofor lowered into the liquor.

A galvanic battery, on the Maynooth arrangement,consisting of a series of ten cells, each being a cast-irontrough, filled with diluted nitric acid. In each cell isplaced a porous cell, charged with diluted sulphuric acid,containing an amalgamated zinc plate.

A galvanic battery, consisting of cells formed of gutta-

percha filled with sand, saturated with diluted sulphuricacid, each cell containing a copper plate, and one ofamalgamated zinc.

Griffin (No. 457, p. 4G3) exhibits graduated glass in-struments, applicable to the examination of carbonate ofsoda and carbonate of potash, of all degrees of impurity,ammonia, sulphuric acid, muriatic acid, acetic acid, andvinegar of all strengths, bleaching powder, aud bleachingliquors generally ; the graduation of these instruments isexecuted on the principle of assigning a fixed volume tothe atomic weights of each chemical compound when insolution, and so producing a series of equivalent testliquors. The standard is made on the consideration that100 grains of oxygen, in a deci-gallon of solution (beingin the proportion of 1,000 grains in a gallon), at thetemperature of 62° Fahr., produce a solution of 100%which represents a quantity of any chemical substanceequivalent to 100 grains of oxygen, or its atomic weightexpressed in grains, contained in a deci-gallon of thesolution.

Thus—

503* 3S grains of hydrate of soda,

667*34 grains of anhydrous carbonate of soda,1792»13 grains of crystalline carbonate of soda,

dissolved respectively in water, so as to make a deci-gallon of solution at 62° Fahr., are of the same chemicalstrength.

In like manner

G43* 19 grains of anhydrous acetic acid,

455* 13 grains of anhydrous muriatic acid,501*165 grains of anhydrous sulphuric acid,202S*64 grains of nitrate of silver,

brought into aqueous solutions of the above bulk at 6*2 3Falir., are all solutions of 100 u of chemical strength. Theextreme convenience of this system carried out in a labo-ratory in respect to the saving of time, thought, and cal-culation, and its power of securing uniformity of manipu-lation, must be obvious to every* chemist.

The graduation of all the glass measures applicable tothese investigations, as well as all others exhibited byMr. Grilfin, is exceedingly accurate and good, the divi-sions from 10° to 10% being performed by Ackland’sgraduating machine, which gives correct aliquant parts.The unit of measure, to which the small measure, calledpipettes and alcaliineters, is referred, is termed by Mr.Griffin the septem , by which is meant the bulk of sevengrains of water, at the temperature and under thebarometric pressure at which the imperial measures areregulated: 1,000septems make a deci-gallon,correspond-ing to 1 lb. avoirdupois of distilled water, and the tenthpart of an imperial gallon of water. The septem, there-fore, is identical with the milli-gallon.

Mr. Griffin exhibits a set of decimal weights andmeasures founded on the imperial gallon and the 1 lb. of7,000 grains.

This Exhibitor, in addition, has given a rich collectionof objects, for the most part similar to those exhibited by rNo. 453, consisting chiefly of apparati for making assayswith the blow-pipe, mineralogical boxes, a large collec-tion of graduated glass apparati, applicable to variouspurposes, boxes fitted with chemical tests, alealimeters,saccharometers, areometers. In the arrangements madeby Mr. Griffin for special purposes, everything necessaryhas been included, to the exclusion of all else, withespecial reference to economy and convenience.

A Prize Medal was awarded to Mr. Griffin.

Edwards (No. 438, p. 461) has exhibited retorts,phials, and capsules, covered with an clectrotyped pre-cipitate of copper, to protect them against cracking byheat; all these articles are good. The covering of glassvessels with copper is not, however, new; but its usewould appear to be very little known in England.

The Jury considered Mr. Edwards deserving of Ho-nourable Mention.

Ibbetson (No. 459, p. 463). Blowing apparatus, con-structed with two circular bellows, for the purpose of acontinuous blast.