H A I 
boiling. It then becomes brittle, the gela- 
tine being the principal cause of its supple- 
ness and toughness. From some experi- 
ments by Mr. Hatchett, it is inferred that 
the hair which loses its curl in moist wea- 
ther, and which is softest and most flexible, 
is that which yields its gelatine most rea- 
dily; whereas strong and elastic hair yields 
it with the greatest difficulty, and in the 
smallest proportion. By an experiment of 
Berthollet’s, 1,152 parts of hair yielded 
Carbonate of ammonia 90 
Water 179 
Oil, .....288 
Gases 271 
Coal 324 
Ti5i 
The oil was soluble in alcohol, burnt with 
brilliancy, and with scintillations like the 
hair itself. The coal was attracted by the 
magnet, which proves it contains iron. The 
alkalies, at a boiling heat, dissolve hair, and 
form with it an animal soap. Sulphuric 
acid dissolves . hair, with the aid of heat. 
Hair is usually distinguished into various 
kinds : the stiffest and strongest is called 
bristles, such as that, on the backs of swine. 
When remarkably soft and pliable, it is de- 
nominated wool, as that on sheep ; and the 
finest of all, is called down. From wool 
more than half its weight of oxalic acid is 
obtained. Feathers possess similar proper- 
ties to those of hair ; the quill is composed 
of coagulated albumen, but no gelatine. 
Muriatic acid dissolves hair, and the solu- 
tion is very like a solution of glue in the 
same acid. When plunged into acid, in the 
state of gas, it is very soon converted into 
a pulp. 
Hair, or Down, of plants, a general 
term, expressive of all the hairy and glan- 
dular appearances on the surface of plants, 
to which they are supposed by naturalists 
to serve the double purpose of defensive 
weapons and vessels of secretion. These 
hairs are minute threads, of greater or less 
length and solidity, some of them visible to 
the naked eye, whilst others are rendered 
visible only by the help of glasses. Exa- 
mined by a microscope, almost all the parts 
of plants, particularly the young stalks or 
stems, appear covered with hairs. Hairs 
on the surface of plants, present themselves 
under various forms; in the leguminous 
plants, they are generally cylindric ; in the 
mallow tribe, terminated in a point; in 
agrimony, shaped like a fish-hook ; in net- 
tle, awl-shaped and jointed; and in some 
HAL 
compound flowers, with hollow or funnel- 
shaped florets, they are terminated in two 
crooked points. 
Hair’s breadth, a measure of length, be- 
ing the forty -eighth part of an inch. 
HAKE, in ichthyology, the English name 
of the gadus, with two fins on the back, and 
the under jaw longest. It grows to two 
feet or more in length, but is the slenderest 
of all the gadi. See Gadus. 
HALBARD, or Halbert, in the art of 
war, a well-known weapon, carried by the 
serjeants of foot and dragoons. It is a sort 
of spear, the shaft of which is about five 
feet long, and made of ash or other wood. 
Its head is armed with a steel point, edged 
on both sides, not unlike the point of a two- 
edged sword : but besides this sharp point, 
which is in a line with the shaft, there is a 
cross piece of steel, flat and pointed at both 
ends ; but generally with a cutting edge at 
one extremity, and a bent sharp point at 
the other; so that it serves equally to cut 
down, or push withal. It is also useful in 
determining the ground between the ranks, 
and in adjusting the files of a battalion. 
HALE, in the sea langauge, signifies 
pull ; as to hale up is to pull up ; to hale in 
or out, is to pull in or out. To over-hale a 
rope, is to hale it too stiff, or to hale it the 
contrary way. 
HALES (Stephen), D. D. in biogra- 
phy, an eminent natural philosopher and 
excellent parish clergyman, was sixth son of 
Thomas Hales, Esq. of Beckesbourn, in 
Kent, where he was born in 1677. At the 
age of nineteen he was entered a pensioner 
of Bene’t College, Cambridge, of which he 
was elected a fellow' in 1702. He after- 
wards proceeded M. A. and entered into 
holy orders. During his residence at Cam- 
bridge he distinguisiied himself by his dili- 
gent researches into various branches of 
natural knowledge, particularly botany and 
anatomy. In these studies he had for an 
associate William Stukeley, afterwards 
M. D. and an eminent antiquary. A turn 
of novel and ingenious experiments, and of 
mechanical inventions, early characterized 
Mr. Hales, and a contrivance for obtaining 
a preparation of the lungs in lead with the 
construction of a planetarium upon the 
Newtonian system of astronomy, are men- 
tioned among the products of his skill at 
this period. In 1710 he was presented to 
the perpetual curacy of Teddington, in Mid- 
dlesex. Not long after he vacated his fel- 
lowship by accepting the living of Portlock, 
in Somersetshire, which he exchanged for 
