most convenient plan for applying phosphorus to illustrate this fact, is to dissolve a small portion in sulphuric ether the size of a pea in an ounce of ether. Experiment 52.-Write with a solution of nitrate of silver; if the page be held over the mouth of the bottle containing the phosphorized ether, the writing becomes visible as the silver is reduced. This should be particularly contrasted with exper. 35, where hydrogen plays the same part. Experiment 53.-Rub a small portion of the phosphorized ether on the hands or face, in the dark it becomes visible-this is extremely harmless. Experiment 54.-Plunge an ignited piece of phosphorus into oxygen, it bursts into a most brilliant flame; or, drop it into a glass vessel containing warm water, and from a bladder, furnished with a stopcock, force oxygen upon it. This presents a splendid illustration of combustion under water. QUESTIONS. 219. What is the derivation of phosphorus ? 220. By whom was it discovered, and in what year ? 221. Who discovered that it could be abundantly obtained from bones? 222. What are bones principally composed of? 223. When bones are burned what portion is destroyed? 224. We say that phosphate of lime is left, what does it consist of? 225. To procure phosphorus sulphuric acid is added, what portion of the phosphate of lime does it attack? The rate at which it is sold when polished is remarkable-a carat weighs only four grains, and sells for eight pounds; two carats are worth thirty-two pounds; three carats, seventy-two pounds; and four carats, one hundred and twenty-eight pounds. The increase of price is arranged thus: the weight of the carats is doubled, and the square of the product is multiplied by two pounds. When the weight amounts to twenty carats the purchasers are but few. One of the largest diamonds that has been discovered belongs to the rajah of Mattan in the East Indies. It is of the purest water, and weighs three hundred and sixtyseven carats. It was discovered about one hundred years since. The emperor of Russia possesses one weighing one hundred and ninety-three carats. It is as large as a pigeon's egg, and was purchased by the Empress Catherine for ninety thousand pounds, with an annuity to a Greek merchant of four thousand. Its history is worth relating:-It was one of the eyes of the statue of Sheringan in the temple of Brama. A French grenadier who served in the Malabar army contrived to steal this gem, and reached Madras in safety, where he sold it for two thousand pounds to a ship-captain, who disposed of it to a Jew for twelve thousand pounds; it passed then into the hands of the Greek merchant, and ultimately was purchased by Catherine. One of the finest diamonds belongs to Louis Philippe of France. It weighs one hundred and thirty-six carats, and is valued at one hundred and sixty thousand pounds. It is named the Regent or Pitt diamond. QUESTIONS. 234. What is the derivation of carbon? 235. Is it abundant? 236. What is the purest specimen ? 237. What is it termed in its impure state? 238. What countries yield diamonds? 239. How much is a carat ? 240. Do you remember the rule for pricing them? 241. Which is the largest diamond? 242. How many carats does the Regent weigh? 243. How are they cut, and when was the art discovered? 244. What are the usual colours? 245. How did Davy prove that diamond was carbon? 246. What did Morveau accomplish by heating diamond enclosed in iron ? 247. What is the chemical name of steel? 65. Carbon tolerably pure is found abundantly in the mineral kingdom-particularly in the various varieties of cOAL. Anthracite or Kilkenny coal is mineral charcoal-differing from common coal in containing scarcely any trace of bitumen. It consequently burns without flame or smoke. COKE principally consists of carbon. It is obtained from gas retorts, after all the volatile portions have been expelled by fire. It produces an intense heat, and burns without smoke, which circumstance renders it valuable for railroads. CHARCOAL is vegetable carbon. It is obtained by exposing wood to an intense heat in covered vessels, |