hard and brilliant, having the formula As 05 + 2 aq. If kept at 392° for some time, and then raised to 402°, the liquid becomes pasty, and at length forms a nacreous white mass of, As 05 + aq. The different hydrates, heated to a dull red heat, give the anhydrous acid, which is quite inert, being insoluble in water, ammonia, &c., and not reddening litmus. It gradually liquefies. Kopp found that if the hands be exposed to the arsenic acid, they at length swell considerably, and serious symptoms may be produced, washing with lime water seems to counteract its effects; the acid could be detected in the excretions, and although no alteration in general health was observed, a very visible in, crease took place in the weight of the body. Phosphoric Acid-Reissig has given a modification of Reynoso's process for the determination of this acid by means of tin; the acid being separated from the oxide by means of sulphuretted hydrogen, and determined by magnesia and ammonia. The process seems to give excellent results, and to be free from some of those objections, which render Reynoso's method inapplicable. Ch. G. 331. H. C. ENGINEERING AND ARCHITECTURE. PRESERVATION OF TIMBER. Plans for the preservation of timber have frequently attracted the attention of men of science, as wood is the most common material used in the arts, and from the acids contained in the sap, the decomposition of the woody fibre speedily commences, where these remain after the vital principle is extinguished by felling the tree. The method employed to eradicate the sap in the ordinary way is by cutting the tree into planks, and exposing the surface of such to the action of the atmospheric air during the heat of Summer. It is found that, according to the climate, from one to two years' exposure, render planks sufficiently seasoned or free from sap, but for large beams, joists, or girders, three or four years, or even a longer time, is necessary. Expensive means have been adopted in England, France, and on the continent of Europe, to imitate this natural process of drying, by placing the beams and planks in a large chamber of wood or metal and passing a current of air through the chamber by means of a fan at a heat considerably more elevated than the natural temperature. This system, although a very good one, involves too great an expense to render its adoption universal; and the joist or plank has to remain from two to three, or even four weeks under this action of hot air, before it is fully seasoned. Another and greatly simpler plan, adopted with some success, is by laying the trees, when fresh felled, in a running stream, when it is found that, after some weeks of immersion, the current has washed out the sap from the minute pores, and substituted the water of the stream. The principle adopted in Mr. Kyan's patent process was the exhaustion, by means of an air pump, of a large cylinder, into which the wood to be seasoned was placed, and when fully exhausted, a solution of corrosive sublimate (chloride of mercury,) was allowed to flow in and enter the pores. Another process adopt ed by Mr. Kyan, was the injection of the same solution by direct pressure; but, in both cases, the great expense prevented the general adoption of plans otherwise perfectly successful. The corsideration of these methods have induced an engineer of Hamilton, Mr. Wm. G. Tomkins, to apply the same ideas more directly and more simply, and we propose to give a short description of a patent obtained by him, from his Excellency the Governor General, dated May 16, 1856, which in its heading enumerates the benefits to be derived as follows: "This Patent consists in the simple manner of inserting in the body of a tree different chemical compounds, by a hydrostatic process, or, by a hydrostatic apparatus, and in the use of a pneumatic apparatus for exhausting and drawing off the sap from a newly felled tree, or by vessels of compressed air, forcing out the sap, thereby seasoning the wood and rendering it more sound and marketable." The manner in which this is effected, is of the utmost simplicity, and can be performed in a few hours at a nominal cost. A tree, newly felled and full of sap, or one in which the sap has been retained, by its lying immersed in water, is laid on the ground and the end cut off by a cross-cut saw, at right angles to the axis of the tree. On to this end is fixed a cap of metal, held firmly by small bolts, which pass through a ring kept in its place by screws or wedges. This hollow cap forms an air-tight chamber, and into the back a pipe is screwed, to connect with a vertical pipe of a quarter inch bore, and a cistern at twenty-five or thirty feet above, for the hydrostatic apparatus, or with a receiver and an airpump for the pneumatic apparatus. By the former process it will be found that, with a head of 25 feet, and pure water in the cistern, a tree of 16 feet in length is permeated by the water in a few seconds, and a stream of sap will run continuously from the other end. By using the pneumatic apparatus, a pressure of 14lbs. to the square inch, equal to a head of water of 28 or 30 feet, will be acting by the weight of the atmosphere, drawing, or so to speak, sucking out the sap which falls into the receiver prepared for it, rendering the tree in a few hours perfectly free from sap; and this without any danger of warping or splitting which constantly takes place in the slower process of seasoning. The quantity of sap which is extracted by this mode equals from 20 to 40 per cent. of the weight of the tree, and hence the saving in carriage, by rail, by ship, or by canal, is of the utmost importance, besides having lumber worth ten per cent. more in the market, as its elements of decay have been withdrawn. After having abstracted the sap, the end of the tree may be immersed in a preservative liquid of any kind, such as corrosive sublimate, sulphate of copper, alum solution, or solution of sulphuric acid, to render the entire body of the tree free from dry-rot and incombustible; or if desirable, a coloring matter may be applied to dye the whole body of the tree, of any hue which may be wanted. In like manner, also, the patentee has impregnated a tree by the hydrostatic process, in a few hours, with the same substance. A tree twelve feet long became brilliantly red throughout in the course of three hours, with two penny worth of logwood: and all other dye stuffs may be used in the same manner. He proposes in his patent, likewise, to use heated air in the pores of the tree, either by the pneumatic process drawing it through the tree, or by compressing the heated air to 10 or 12 pounds to the inch; and then, as it were, blowing out the sap. Either mode may be adopted, and the expense is trifling. In our large Canadian saw mills, where 250 or 300 logs are passed under the saw in the day, all might be prepared the previous day with one or two pumps, and a sufficient number of caps, the fixing of which would not occupy more than the attention of one man. The pumps at a cost of $30 or $40, would be worked by the motive power of the mill. The utility of this simple invention cannot be overrated, when we consider that Canada produced in 1853 the enormous quantity of 218,480,000 feet of lumber, and 38,740,000 cubic feet of squared timber, which would be worth, as declared by the Government accounts, £2,355,255. This is entirely for export, and we may safely estimate that the quantity required for home consumption, for railroads, bridges, shipping, houses, &c., must considerably exceed double this quantity. Any method which can be adopted to prevent the ravages of dry rot and decomposition, must prove an absolute saving to the country to a very considerable amount. These processes which we have briefly attempted to describe, seem to embody the requirements of simplicity and easiness of application; and, if they are proved by practical experience to accomplish all that their patentee promises, could be introduced, at a very slight expense, in the largest as well as the smallest lumber mills. With such a simple method, our houses and bridges might be made capable of lasting an indefinite period. It is worthy of notice, in reference to these processes, that they serve in some degree to illustrate the small amount of pressure which nature seems to employ in the growth of trees. We here find, that with a head of twenty-five feet, water is driven, in about thirty seconds through a tree 16 feet long; so that in the natural process of the sap rising, the pressure must be scarcely perceptible, and probably, is nothing more than capillary attraction. When looking at the end of a beach or oak log, with its extremely minute pores, it would scarcely be believed that so slight a pressue could force the water through its minute channels, yet such appears to be the case, and it is owing to this wonderful provision of nature, that by the processes detailed above, these same pores may be employed as means of drying and seasoning the wood; or conveying through them, to the innermost heart of the tree, chemical substances, to render it incombustible, or completely to impregnate it with any coloring matter we may desire. Scarcely anything strikes the observant traveller fresh from Europe, on his first arrival in Canada, more than the extent to which wood is used; especially in great public works, such as Railway viaducts, and bridges of all kinds, in piers and esplanades, and in many parts of the most substantial buildings, for which stone or iron would alone be considered suitable in Europe. The cause of this is obvious, from the great abundance, slight cost, and facility in working, of the wood; and if to these important qualities we can only add something of the permanency of stone and iron, by such economical processes as those referred to above; and further render it incombustible, as has been effectually, though not yet economically done, by Kyan's methods, the value of the results to Canada would be almost incalculable. One, if not both of these most desirable objects, Mr. Tomkins, of Hamilton, believes he has attained; and we can only hope his processes will be fairly and fully tested; and that if they prove successful he may meet with the reward he will be so fully entitled to. F. W. C. MONTHLY METEOROLOGICAL REGISTER, AT THE PROVINCIAL MAGNETICAL OBSERVATORY, TORONTO, CANADA WEST-AUGUST, 1856. Latitude-43 deg, 39.4 min. North. Longitude-79 deg. 21 min. West. Elevation above Lake Ontario, 108 feet. Velocity of Wind. Direction of Wind. 6 A.M. 2 P. M. 10P.M. MEAN 6 A.M2 P.M 10PM ME'N of the 6 2 10 Μ' I'N Rain in Inches. 1234569 .455 65-3 74-1 56.4 72.9 29.694 29-656 29.581 29-6395 59.2 81.3 71.4 71.20+ 4.23.426.525.462.485.87 .51.62 .67 .575 .656 •633 .654 4843 65.480.570.4 72.60 +5.75.477.605.579.559.78 6158 61.9 74.7 62.5 67.17 +0.37.440.436.433.454.82 64.58 .61 17 .753 .719 57-470.4 2.32-446-592-374.450 84 80.82 78 M 29.5310 29.5072 29.5238 29.5208 57.90 70.58 60.48 63.59 .483.608 86.79 13.85 316 248-236-252-88 538170 84.38 2.17.401.450.402.419.85 1.62 1.77 1.73 S 75 W 8.8 10.8 7.2 5.96 7.01 0.035 6.0 8.8 3.6 6.54 7.61 0.0 15.8 3.2 5.38 6.38 Inap 4.2 15.8 2.6 7.16 7.81 0.020 2.6 11-2 5.0 5.81 7.87 0.040 S 85 W 0.0 4.0 3.5 1.49 4.63 REMARKS ON TORONTO METEOROLOGICAL REGISTER FOR AUGUST. 29.797 at 2 p. m., on 31st Monthly range= 29.174 at 10 p. m., on 19th S 0.623 inches. 8207 at p. m., on 2nd) Monthly range= 41°2 41°5 at a. m., on 26th S 2nd Mean temperature.. Greatest intensity of Solar Radiation Difference 21°72. Auroral Light observed on 5 nights, viz., 6th, 22nd, 23rd, 24th, and 31st; possible to see Aurora on 22 nights; impossible to see aurora on 9 nights. No Snow this month. Raining on 12 days,-depth 1.680 inches-raining 23.6 hours. Sum of the Atmospheric Current, in miles, resolved into the four Cardinal Lightning not accompanied by thunder occurred on 5 days. The total displacement of air during the month was equal to that produced by a directions. South. East. West. Resultant direction of the wind, N 50° W.; Resultant Velocity 2.87 mils. Mean velocity of the wind......... 7.03 miles per hour. Least windy day 27th... Mean velocity 2.80 ditto. Most windy hour 2 to 3 p. m.... Mean velocity 10.75 dilto. |