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 In the natural state, phosphorus is found combined'with lime in the form of an acid, forming phosphate of lime, which is the composition of bones.
OF SULPHUR.
138. Sulphur is a well 'known substance of a yellow colour, without much taste and without smell unless it is heated or rubbed. So far as is known, it is a simple body. It exists in nature in great abundance, being found in the animal, vegetable, and mineral kingdoms : but chiefly in the latter. .
Obs. The sulphur of commerce is chiefly dug out of the earth in volcanic countries, or in the craters of extinct volcanoes. It is deposited in these places by sublimation, being brought up by the heat from the depths below, where it existed in combination with metallic substances. It is also obtained, of an inferior quality, during the process of refining coppor ore.
139- When sulphur is heated to a little above the temperature of boiling water, it melts and becomes completely fluid. But it is a singular fact, that if the heat be raised much above this, it again becomes solid, and becomes fluid again as the temperature is reduced.
If after it is melted, it is safiered to cool, it shoots into crystals.
140. When sulphur is in complete fusion, if it is poured into.water it becomes soft and tenacious like wax.
Obs. in this slate it is made use of to take impressions from medals and engraved stones, and as it soon becomes hard, it will retain tni impression for any length of time.
141. When sulphur is exposed to a beat of about 300 degrees, it sublimes, or is converted into vapor.
Obs. In this stale it is called Jlawers of sulphur, and differs from brimstone only in being more pure, and in a state of minute division
142. Sulphur combines with the earths, alkalies, and metals, and forms a class of compounds called sulphurets.
143. It unites to oxygen in two proportions and forms two acids, the sulphurous and sulphuric : see acids.
144. It unites with hydrogen, forming sulphuretted hydrogen This substance is extricated from animal substances during their decomposition, and is chiefly the cause of the disagreeable smell.
Carbon is a constituent of all vegetable and animal substances. When perfectly pure and crystallized, it constitutes the most costly of all substances, the diamond.
Obs. If carbon could be crystallized by art, the diamond would immediately lose a great part of its value. But as yet, this has been effected in the labratory of nature alone.
146. The method of making charcoal is by submitting wood, to a red heat, having it covered from the contact of the air.
Example. Expose wood of any kind, stripped of its bark, to a red heat in a close vessel, till vapors cease to issue, and you obtain a black, opake, brittle substance, easily reduced to powder, and without taste or smell. This is charcoal.
Obs. If you pound it and wash away the salts it may contain by dilute muriatic acid, and afterwards, by repeated effusions of cold water, and then dry it at a low red heat, you obtain it sufficiently pure for experiment. Common charcoal dried in an oven will do, where great nicety is not required.

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