PHO 
PHO 
V H R 
lowing process : Let a quantity of bones be 
burnt, or, as it is termed in chemistry, cal- 
cined, till they cease to smoke, or to give 
out any odour, and let them afterwards be re- 
duced to a line powder. Put 100 parts of 
this powder into a bason of porcelain or 
stone ware, dilute it with four times its weight 
of water, and then add gradually (stirring the 
mixture after every addition) 40 parts of 
sulphuric acid. The mixture becomes hot, 
and a vast number of air-bubbles are extri- 
cated. Leave the mixture in this state for 
24 hours ; taking care to stir it well every 
now and then with a glass or porcelain rod, 
to enable the acid to act upon the powder. 
The whole is now to be poured on a filtre 
of cloth; the liquid which runs through the 
filtre is to be received in a porcelain bason ; 
and the white powder which remains on the 
filtre, after pure water has been poured on it 
repeatedly, and allowed to strain into the 
porcelain bason below, being of no use, may 
be thrown away. 
Into the liquid contained in the porcelain 
bason, which has a very acid taste, sugar of 
lead, dissolved in water, is to. be poured 
slowly; a white powder immediately falls to 
the bottom: the sugar of lead must be added 
as long as any of this powder continues to be 
formed. Throw the whole upon a filtre. 
The white powder which remains upon the 
filtre is to be well washed, allowed to dry, 
and then mixed with about one-sixth of its 
weight of charcoal-powder. This mixture is 
to be put into an earthenware retort. The 
retort is to be put into a sand-bath, and the 
beak of it plunged into a vessel of water, so as 
to be just under the surface. Heat is now to 
be applied gradually till the retort is made 
red-hot. A vast number of air-bubbles issue 
from the beak of the retort, some of which 
take fire when they come to the surface of 
the water. At last there drops out a sub- 
stance which has the appearance of melted 
wax, and which congeals under the water. 
This substance is phosphorus. 
Properties. 1. Phosphorus, when pure, is 
semitransparent, and of a yellowish colour ; 
but when kept some time in water, it becomes 
opaque externally, and then has a great re- 
semblance to white wax. Its consistence is 
nearly that of wax ; it may be cut with a 
knife, or twisted to pieces with the fingers (a 
dangerous process). It is insoluble in water. 
Its mean specific gravity is J .77. 
2. It melts at the temperature of 99°. 
Care must be taken to keep phosphorus 
under water when melted ; for it is so com- 
bustible, that it cannot easily be melted in 
the open air without taking fire. When 
phosphorus is newly prepared, it is always 
dirty, being mixed with a quantity of char- 
coal-dust and other impurities. These im- 
purities may be separated by melting it under 
water, and then squeezing it through a piece 
of clean shamoy-leather. It may be formed 
into sticks, by putting it into a glass funnel 
with a long tube, stopped at the bottom with 
a cork, and plunging the whole under warm 
water. The phosphorus melts, and assumes 
the shape of the tube. When cold, it may 
be easily pushed out with a bit of wood, if 
air is excluded, phosphorus evaporates at 
2 19°, land boils at 554°. 
3. When phosphorus is exposed to the at- 
mosphere, provided the temperature is not 
lower than 43°, it emits a white smoke, which 
has the smell of garlic, and is luminous in the 
dark. This smoke is more abundant the 
higher the temperature is, and is occasioned 
by the gradual combustion of the phospho- 
rus, which at last disappears altogether. 
4. When a bit of phosphorus is put into a 
glass jar filled with oxygen gas, part of the 
phosphorus is dissolved by the gas at the 
temperature of 60°; but the phosphorus does 
not become luminous unless its temperature 
is raised to 80°. Hence we learn, that phos- 
phorus burns at a lower temperature in com- 
mon air than in oxygen gas. This slow com- 
bustion of phosphorus, at the common tem- 
perature of the atmosphere, renders it neces- 
sary to keep phosphorus in phials filled with 
water. The water should be previously 
boiled to expel a little air, which that liquid 
usually contains. The phials should be kept 
in a dark place ; for when phosphorus is ex- 
posed to the light, it soon becomes of a white 
colour, which gradually changes to a dark 
brown. When thus altered, the French 
chemists give it the name of oxide of phos- 
phorus ; supposing it now to be no longer 
pure phosphorus, but phosphorus combined 
with a little oxygen. Phosphorus, when 
newly prepared, always contains some of this 
oxide of phosphorus mixed with it; but it 
may be easily separated by plunging the mass 
into water heated to about 160°. The phos- 
phorus melts, while the oxide remains un- 
changed, and swims upon the surface of the 
melted phosphorus. 
5. When heated to 148°, phosphorus takes 
fire and burns with a very bright flame, and 
gives out a great quantity of white smoke, 
which is luminous in the dark ; at the same 
time it emits an odour which has some resem- 
blance to that of garlic. It leaves no resi- 
duum ; but the white smoke, when collected, 
is found to be an acid. 
On examining the acid produced during 
the combustion of phosphorus, it is found 
that it is a peculiar acid, now known by the 
name of phosphoric acid, which see. 
The combustion of phosphorus, like that 
of sulphur, is nothing else than its combina- 
tion with oxygen: for during the process no 
new substance appears, except the acid, ac- 
companied indeed with much heat and light. 
6. Phosphorus combines readily with sul- 
phur, and the two substances are capable of 
being mixed in different proportions. Seven- 
ty-two grains of phosphorus and nine of sul- 
phur, when heated in about four ounces of 
water, melt with a gentle heat. The com- 
pound remains fluid till it is cooled down to 
77°, and then becomes solid. These sub- 
stances were combined in the same manner 
in the following proportions : 
4 Phosphor u 
1 Sulphur 
4 Phosphorus) 
2 Sulphur 5 
4 Phosphorus ) 
4 Sulphur 5 
4 Phosphorus) 
12 Sulphur ) 
congeals at 59® 
at 50® 
at 4 1® 
at 99'. 
} 
When the phosphorus predominates, this 
compound is called phosphuret of sulphur ; 
when the sulphur exceeds, it is called sul- 
phuret of phosphorus. 
Phosphorus and sulphur may be combined 
also by melting them together without any 
water; but the combination takes place so 
3G2 
41 9 
rapidly, that they are apt to rush out of the 
vessel if the heat is not exceedingly mode- 
rate. 
7. Phosphorus is capable likewise of com- 
bining with many other bodies ; the com- 
pounds produced are called phosphurets, 
which see. 
8. Phosphorus, when used internally, is 
poisonous. In very small quantities (as one- 
fourth of a grain), yet when very minutely 
divided, it is said by Leroi to be very effica- 
cious in restoring and establishing the force 
of young persons exhausted by sensual indul- 
gence. 
The affinities of phosphorus have not yet 
been ascertained. 
PHOSPHURETS, substances formed by 
an union of the alkalies, earths, and metallic 
oxides, with phosphorus. Thus we have piios- 
phuret of lime, &c. 
Phosphuret of Antimony. When equal 
parts of antimony and phosphoric glass are 
mixed together with a little charcoal-powder, 
and melted in a crucible, phosphuret of anti- 
mony is produced 
Phosphuret of Barytes may be formed 
by putting a mixture of phosphorus and ba- 
rytes into a glass tube close at one end, and 
heating the mixture by putting the tube upon 
burning coals. These instances will be suf- 
ficient to explain the nature of phosphurets 
in general. 
PIIOTINIANS, a sect of Christians in the 
fourth century, so called from Photinus, their 
chief, who was bishop of Sirmich, and main- 
tained that Jesus Christ was true man, but 
not true God, nor born before all ages ; and 
that he only began to be Christ when the 
Holy Spirit descended upon him in the river 
Jordan. 
PHOTOMETER, Measurer of Light, 
in a cloudy or bright day, or between differ- 
ent luminous bodies. A good instrument of 
this kind is still a desideratum in philosophy. 
PHRASE, in grammar, a manner of 
speech peculiarly adapted to certain occa- 
sions, arts, languages, &c. 
PHRENETIC VESSELS. See Anato- 
my. 
PHRENSY. See Medicine. 
PHRYGANEA, a genus of insects of the 
order neuroptera. The generic character is, 
mouth without teeth, with four feelers ; stem- 
mata three ; antennae longer than thorax ; 
wings incumbent, the lower pair pleated. 
The genus phryganea consists of insects 
which in point of habit or general appear- 
ance bear a considerable resemblance to some 
of the phalange, and particularly to those be- 
longing to the division entitled tines. They 
may however be readily distinguished from 
moths by their palpi o v r feelers, as well as by 
the stemmata situated on the top of the 
head. The phryganea? proceed from aquatic 
larva? of a lengthened shape, residing in tubu- 
lar cases, which they form by agglutinating 
various fragments of vegetable substances, 
particles of gravel, &c. &c. These tubular 
cases are lined within by a tissue of silken 
fibres, and are open at each extremity. 
The included larvae, when feeding, protrude 
the head and fore parts of the body, creep- 
ing along the bottom of the waters they in- 
habit, by means of six short and slender legs: 
on the upper part of the back, in most spe- 
cies, is situated an upright papilla or process. 
