PHO 



PHO 



The whole is again to be poured upon a 

 filter, ui.d the white powder which re- 

 niain! is to be well washed and dried. 

 The dried powder is then to be mixed 

 with one-sixth of its weight of charcoal 

 powder. Put this mixture into an earth- 

 enwave retort, and place it in a sand bath, 

 with the beak plunged into a vessel of 

 waler. Apply heat, and let it be gradual- 

 ly increased, till the retort becomes red 

 hot. As the heat increases, air bubbles 

 rush in abundance through the beak of 

 the retort, some of which are inflamed 

 when they come in contact with the air at 

 the surface of' the. water. A substance at 

 last drops out similar to melted wax, 

 which congeals under the water. This is 

 phosphorus. To have it quite pure, 

 melt it in warm water, and strain it sever- 

 al times through a piece of shamoy lea- 

 ther under the surface of the water. To 

 mould it into sticks, take a glass funnel 

 with a long tube, which must be stopped 

 with a cork. Fill it with water and put the 

 phosphorus into it. Immerse the funnel 

 in boiling water, and when the phos- 

 phorus is melted, and flows into the 

 tube of the funnel, then plunge it into 

 coid water, and when the phosphorus 

 has become solid, remove the cork, and 

 push the phosphorus from th mould 

 with a piece of wood. Thus prepared, it 

 must be preserved in close vessels, con- 

 taining pure water. When phosphorus 

 is perfectly pure, it is semi-transparent, 

 and has the consistence of wax. It is so 

 soft that it may be cut with a knife. Its 

 specific gravity is from 1.77 to 2.03. It 

 has an acrid and disagreeable taste, and 

 a peculiar smell, somewhat resembling 

 garlic. 



When a stick of phosphorus is broken, 

 it exhibits some appearance of crystalliza- 

 tion. The crystals are needle shaped, 

 or long octahedrons ; but to obtain them 

 in their most perfect state, the surface of 

 the phosphorus, just when it becomes so- 

 lid, should be pierced, that the internal 

 liquid phosphorus may flow out, and 

 leave a cavity for their formation. When 

 phosphorus is exposed to the light, it be- 

 comes of a reddish colour, which appears 

 to be an incipient combustion. It is 

 therefore necessary to preserve it in a 

 dark place. At the temperature of 99 

 it becomes liquid, and if air be entirely 

 excluded, it evaporates at 219, and boils 

 at 554. At the temperature of 43 or 

 44, it gives out & white smoke, and is 

 luminous in the dark. This is a slow 

 combustion of the phosphorus, which be- 

 comes more rapid as the temperature is 



raised. When phosphorus is healed to 

 the temperature of 148 it takes fire, 

 burns with a bright flame, and gives out 

 a great quantity of white smoke. Phos- 

 phorus enters into combination with oxy- 

 gen, azote, hydrogen, and carbon Phos- 

 phorus is soluble in oils, and when thus 

 dissolved, forms what has been called li* 

 quid phosphorus, which may be rubbed 

 on the face and hands without injury. It 

 dissolves too in ether, and a very beauti- 

 ful experiment consists in pouring this 

 phosphoric ether in small portions, and 

 in a dark place, on the surface of hot wa- 

 ter. The phosphoric matches consist of 

 phosphorus extremely dry, minutely di- 

 vided, and perhaps a littie oxygenized. 

 The simplest mode of making them is to 

 put a little phosphorus, dried by blotting 

 paper, into a small phial ; heat the phial, 

 and when the phosphorus is melted turn it 

 round, so thai the phosphorus may adhere 

 to the sides. Cork the phial closely, and it 

 is prepared. On putting a common sul- 

 phur match into the bottle, and stirring 

 it about, the phosphorus will adhere to 

 the match, and will take fire when 

 brought out into the air, 



PHOSPHURETS, in chemistry, are 

 substances formed by an union with phos- 

 phorus ; thus we have the phosphuret of 

 carbon, which is a compound of carbon 

 with phosphorus : we have also the phos- 

 phuret of lime, hydrogen, &c. 



PHOSPHURETIED hydrogen, phos- 

 phorus dissolved in hydrogen gas ; which 

 may be done by introducing phosphorus 

 into a glass jar of hydrogen gas standing 

 over mercury, and then melting it by 

 means of a burning glass ; the gas dis- 

 solves a large proportion of it. The 

 compound has a very fetid odour, some- 

 thing like that from putrid fish. When 

 it comes into contact with common air, it 

 burns with great rapidity, and if mixed 

 with that air 'it detonates violently. Oxy- 

 gen gas produces a still more rapid and 

 brilliant combustion than common air. 

 When bubbles of it are made to pass up 

 through water, they explode in succes- 

 sion as they reach the surface of the li- 

 quid ; a beautiful column of white smoke 

 is formed. This gas is the most combus- 

 tible substance known. Its combustion 

 is the combination of its phosphorus and 

 hydrogen with the oxygen of the atmos- 

 phere, and the products are phosphoric 

 acid and water. These substances mix- 

 ed or combined, constitute the white 

 smoke. 



PHOTOMETER, an instrument intend- 

 ed to indicate the different quantities of 



