YOUNG MEN'S CHRISTIAN ASSOCIATION. NATURE'S CHEMISTRY.

Daily Southern Cross, Volume XXXII, Issue 5205, 17 June 1876, Page 1 (Supplement)

YOUNG MEN'S CHRISTIAN ASSOCIATION. NATURE'S CHEMISTRY.

The large room of the Young Men's Christian Association was crowded last night to hear the first lecture of the winter course. The lecturer was Mr. Josiah Martin, of the Model School, *nd the subject " Nature's Chemistry." The platform presented a very unusual appearance. It had several tables upon it, winch were covered with specimens ot various minerals and chemicals and chemical appliances. On the wall behind the platform were hung a score or so of diagrams, and on the left of the platform was a large white screen. Shortly after half-past seven o'clock, Colonel Haultain took the chair, and called upon the Rev. Mr. Ashwell to open the proceedings with prayer. This done he introduced the lecturer in a few appropriate words. Mr. Martin began by stating that his subject was as wide as nature itself, and as far as it was concerned he was at liberty to ramble over the whole world, and, indeed, from this world to others. He would not, however, tire their patience by expatiating at large upon nature's chemistry, but would direct their attention specially to the history of one of the commonest substances in nature —a piece of limestone —and show the important part it and its constituents play in the chemistry of nature. In treating this, he would not weary them with the dry abstract of the subject, bnt would illustrate it as he went on by experiments, lime-light views, &c. If they tound that he treated the subject in too simple a manner, they must remember that he was only a schoolmaster. The lecturer then took a solution of lime, which was perfectly colourless. He breathed into it until it became quite milky. He poured some of the solution on to a pane of glass, and in a short time showed that the appearance had been quite altered from the effect of the breath of the audience. The change had been caused by carbonic acid gas. Now, what is carbon? and how is it in our breath? He showed a piece of charcoal. This exists in food aa might be seeu in burnt toast and overdone pie' Examples of carbon are the diamond black lead aud coke. Loaf sugar contained it. This lie proved by dissolving some in hot water, and adding sulphuric acid. The result was an intensely black liquid. Carbon is in all our food. On the average the amount of carbon in our food per day necessary to support life, is 12 ounces. The inhabitants ot warm climates required less, those of cold climates more, as carbon is the cause of our bodily heat. The lecturer burnt some charcoal in oxygen gas. Coal, coke, and gas owe their heating qualities to the quantity of carbon they contain. In giving forth that heat, they displayed What was called eneigy. Energy he explained meant "power at work." This energy has been accurately measured. One pound ot carbon would litt itself 2,000 miles, or litt a weight of 5,000 tons to the height of one foot. 7721b falling one foot, and then suddenly stopped, would generate sufficient heat to raise the temperature of water one degree of .Fahrenheit. The piece of coal he had in his liand, if composed of pure carbon, should raise the temperature of 12 gallons of water from 60 degrees to 212 degrees, that is, wouldmaketbatquantityoC water boil. Housekeepers would laugh at him for saying so, because they knew practically that it took ten times that quantity, but this \t as because so much of the heat was wasted in warming the ground and the air around the pot, and so much went up the chimney. Ordinary air contains about four parts carbonic acid in 10,000. A cubic foot of carbonic gas weighs 016 grains, and contains about a drachm of carbon. The room they were in he had measured, aud found to contain about 32,600 cubic feet. The air in it would contain about 12 cubic feet of carbonic acid, and this would be equal to about iive ounces of black lead, so that if it could be precipitated they <would see a very fine ihower of 3mufcs falling about them. A man breathes out 3,123ft. of this gas every day. A candle did about the same ; gas jets did eight or ten times as much. The lecturer adverted to the amount of this gas produced in crowded and brillliantly lighted public buildings, and to the immense amount produced in the United Kingdom by the consumption of coal. He produced the gas by pouring hydrochloric acid upon some limestone. The gas extinguished a lighted taper. Ho lighted some potassium by dropping it into water, and afterwards caused it to burn in carbonic acid to show that, though, not a supporter of combustion, it was possible for tire to exist in it. The lecturer went into statistics showing the amount of oxygen given off by the leaf suifacc of trees and by cultivated ground, and dwelt upon the necessity of maintaining forests, which are the great lungs of the world. In former ages of the world's existence it was possible that animal life had increased to that extent that more carbonic acid was produced than could be counter-balanced by the oxygen given off by plants. This would produce a hot, moist, enervating climate, which would promote the growth of vegetation whilst unfavourable to animal life, and so the balance would be restored. The next experiment was the slacking of lime with water. The heat from this was made to ignite gunpowder. This heat had been utilised for making gas, and forcing vines very successfully. The lecturer explained the actiiu of sand upon lime or mortar, as forming points for crystallization to centre upon. He touched upon the method of making soda water and lemonade, which was merely water with carbonic acid gas forced into it. The carbonic acid from the decayed vegetation of the earth was carried by rain, partly into the earth, where it formed deposits of carbonate of lime, and partly to the sea. — Mr. Dennes here showed, in the oxyhydrogen lamp, the interior of a cavern in a stratum of carbonate of lime, and pictures of coral polyps at work, of coral reefs, &c—Mr. Howard and his daughters then bang very nicely " The Mermaid's Song," Other pictures of fossils, and of the springs of Kotomahana Giant's Causeway. Falls of Niagara, &c., were exhibited to showt he differ)! ent agencies at work in nature, in whichlimestone played a principal part. The lecturer adverted to the difficulty experienced in assigning any definite periods for the formation of strata. He instanced Kent's Cavern, at Torbay, of which he gave a graphic description. A deposit of a iilmlike nature the 20th of an inch in thickness had taken ISi years to form. From this it was calculated that it would take about 4,000 years to make an inch ; yet he had there a deposit 2h inches thick which had been found in the Pumping shaft at the Thames in ten months. Such a fact wonld come like a bomb-shell upon those who maintained that Kent's Cavern proved an antiquity of about 240,000 years. A number of buildings and statues were now shown by Mr. Dennes as exemplifying the uses made of limestone. Whilst a view of Netley Abbey was exhibited, the choir sang the "Alma Redemptoris Mater," and when the tomb of the Black Prince was being admired they sang "My People." Mr. Martin concluded his very interesting lecture by calling on his auditors to recognise the hand of the Creator in the works of nature, and to learn from the greaS part which insignificant polyps played, how important were the apparently trifling dunes each of us had to perform.—Mr. ThomaB Macffarlane moved, and Mr. Holdship seconded, a vote of thanks to Mr. Marinn, which was carried with acclamation.—Mr. Martin ao - kaowledged his obligations to Mr} Howard and his daughters tor their musical assistance, and to Mr. Dennes for his pictorial illustrations. He announced that the lastnamed gentleman wonld exhibit his splendid series of IriBh and Scottish views in about a fortnight. The proceedings then closed.