PHOSPHORUS. 



541 



presented a luminous appearance; but he found the 

 cloth covered with luminous specks, that resembled 

 the ova of fish, both in form and size. On examining 

 them with a lens, he perceived that they had internal 

 motion, and on some of them being put into the 

 water, they swam quickly about. One of these was 

 seized with a pair of forceps, which caused it to shed 

 a shining liquor of a blue colour, which illuminated 

 the water for several lines. We have given a re- 

 presentation of this animal at fig. 32. Riville says, 

 that the liquor does not mix with the water, but 

 floats on the surface, like globules of oil, and shines 

 with a phosphorescent lustre. 



Captain Horsburg, and many others since his time, 

 have ascertained that the luminous state of the sea, 

 between the tropics, is caused by marine animals 

 floating upon the surface of the water. Fig. 51 re- 

 presents one of the animals which he discovered. 



Mr Baird, in mentioning the medusa scintillans, 

 says, that their size is about that of a grain of sand; 

 but, when seen shining in the water, their apparent 

 size was very much increased. Upon taking up a 

 bucket full of water, from alongside the ship, and 

 pouring it upon the deck, innumerable spots might 

 be seen about the size of small peas, which, when 

 taken up on the finger, and carried to a light, were 

 scarcely discernible to the naked eye. Magnified 

 thus by the refraction of the water and their own 

 light, when the countless millions of them were 

 scattered about upon the surface of the sea, upon its 

 being agitated and set in motion by the ship's way 

 through it, the appearance then presented was 

 beautiful in the extreme. He mentions having met 

 with a single specimen of medusa, in the straits of 

 Banca, which he placed in a wine-glass full of clean 

 sea-water, and kept it till evening. When taken 

 to a dark place, the water upon its surface being 

 struck and agitated by the finger, immediately gave 

 out several bright sparks. This luminousness, how- 

 ever, soon ceased, the agitation of the water being 

 continued; but when left undisturbed for some time, 

 it seemed to recover its power, again emitting flashes 

 of light upon being struck smartly with the top 

 of the finger. 



Dr MacCulloch states, that the luminous appear- 

 ance of the sea is never seen when the ocean presents 

 a blue colour, as then there are no animalcules 

 present in it. Mr Baird, however, says, that he has 

 frequently caught animalcules in it while it appeared 

 blue; and he denies the assertion, that the luminous 

 appearance is a precursor of a storm; and that, on 

 the contrary, he conceives that they rather retire to 

 the depths of the ocean before a change of weather. 



It seems evident from all the observations which 

 have been made, that the luminousness of the ocean 

 depends in a great measure upon the animals above 

 described, and others. But Mr D. Sharpe, in a 

 voyage to Lisbon, particularly examined water 

 presenting a phosphorescent appearance, emitting a 

 light resembling the smallest stars in brightness. 

 When a bucketful was taken up, nothing was visible 

 until it was shaken, when it was instantly filled with 

 spangles, which disappeared as the water settled. 

 On carefully examining this water with a microscope, 

 nothing could be detected but an abundance of small 

 fibres and shreds of apparently animal matter; and 

 hence he infers that the phosphorescence of the 

 ocean in some cases arises from the particles of dead 

 fishes, &c. 



PHOSPHORUS was discovered by Brandt in 

 1669, though there are some reasons for believing 

 that the alchemists of an earlier period were also 

 acquainted with this substance. Brandt kept his 

 process secret for some time. Kunckel, another 

 German chemist, knowing only that Brandt had 



procured it from urine, entered on the investigation, 

 and succeeded in discovering the process. Mr Boyle, 

 in England, also discovered it, and Godfrey Hank- 

 witz, a man who was taught the process by Boyle, 

 sold it for many years, at a high price, in London. 

 In 1769, Ghau, a pupil of Scheele of Sweden, having 

 discovered that phosphate of lime is the basis of 

 bones, invented the process now generally followed. 

 It is as follows : 100 parts of burnt bones in powder 

 are to be mixed with forty parts of sulphuric acid, 

 and they are to be suffered to remain in contact for 

 two days, the mixture being frequently stirred. The 

 whole is then to be poured upon a filtre of cloth, and 

 the liquor that passes through is to be added to a 

 nitrous solution of lead ; a white powder will be 

 formed ; this must be mixed with about one fifth of 

 its weight of charcoal powder, and exposed to a 

 strong red heat in a porcelain retort, the beak of 

 which is plunged in water ; much gaseous matter 

 will come over, some of which will inflame sponta- 

 neously, and at length a substance will drop out of 

 the neck of the retort, and congeal under the water, 

 which is phosphorus. It may be purified by melting 

 it in water, and passing it under water through cha- 

 mois leather. It is semitransparent, and of a white, 

 or yellowish-white colour ; it is as soft as wax ; in- 

 soluble in water ; specific gravity, 1.77. It melts at 

 the temperature of 90 Fahr., and boils at 550. 

 When phosphorus is exposed to air at common tem- 

 peratures, it emits a white smoke, which appears 

 luminous in the dark. This depends upon its com- 

 bining with oxygen, and forming an acid which 

 unites with the aqueous vapour in the atmosphere, 

 and they fall down in the fluid form. When phos- 

 phorus is heated to about 148, it takes fire, and burns 

 with intense brilliancy, throwing off dense white 

 smoke, which is a strong acid, that soon becomes 

 liquid by taking moisture from the air. It forms 

 three acids by combining with oxygen. When it is 

 inflamed in oxygen gas over mercury, and the white 

 substance produced strongly heated, the oxygen 

 being in excess, for every grain of phosphorus burnt, 

 four and a half cubic inches of oxygen are absorbed. 

 The substance so procured is phosphoric acid. It 

 becomes fluid at a red heat, and is not volatile, even 

 at a white heat. Its taste is intensely acid. It acts 

 upon and corrodes glass, and unites with alkalies and 

 oxides. When phosphorus is heated in highly rare- 

 fied air, three products result ; one is phosphoric 

 acid, another is an easily volatile substance, appear- 

 ing as a white powder, and the third is a red solid, 

 requiring a heat above that of boiling water for its 

 fusion. The second substance is soluble in water, 

 and the solution is possessed of acid properties. It 

 contains less oxygen than the phosphoric acid ; for 

 it burns and becomes fixed when heated in the air. 

 It is phosphorous acid. The third substance requires 

 less oxygen than phosphorus to convert it into 

 phosphoric acid, and is regarded as an oxide of phos- 

 phorus. Phosphorus burns in chlorine gas, and unites 

 with it in two proportions, the one of which contains 

 twice as much chlorine as the other. When these 

 are thrown in water, the chloride is resolved into 

 muriatic and phosphorous acids, the bi-chloride into 

 muriatic and phosphoric acids. Iodine also acts 

 upon phosphorus at common temperatures. It forms 

 with sulphur, compounds more inflammable than pure 

 phosphorus. It is soluble in alcohol, ether, and the 

 expressed or volatile oils, especially by the aid of a 

 little heat. The solutions in oils are luminous when 

 exposed to the air. The compounds formed by 

 phosphoric acid with the alkalies, earths and metal- 

 lic oxides, are called the phosphates. Phosphates of 

 alkalies are partially decomposed by heating with 

 charcoal ; phosphate of ammonia is decomposed by 



