HAIR. 
the extremities, but the whole changes co- 
lour at once, and the like is observed in 
boys, &c. ; which shows, that there is a di- 
rect communication, and that all the parts 
are affected alike. It may be observed, 
however, that, in propriety, the life and 
growth of hairs is of a different kind from 
that of the rest of the body, and is hot im- 
mediately derived therefrom, or recipro- 
cated therewith. It is rather of the nature 
of vegetation. They grow as plants do out 
of the earth ; or, as some plants shoot from 
the parts of others, from which though they 
draw their nourishment, yet each has, as it 
were, its several life, and a distinct economy. 
They derive their food from some juices in 
the body, but not from the nutritious juices ; 
whence they may live though the body be 
starved. 
The hairs ordinarily appear round or cy- 
lindrical ; but the microscope also discovers 
triangular and square ones, which diversity 
of figure arises from that of the pores, to 
which the hairs always accommodate them- 
selves. Their length depends on the quan- 
tity of the proper humour to feed them, 
and their colour on the quality of that hu- 
mour: whence, at different stages of life, 
the colour usually differs. Their extremi- 
ties split into two or three branches, espe- 
cially when kept dry, or suffered to grow 
too long ; so that what appears only a sin- 
gle hair to the naked eye, seems a brush to 
the microscope. The hair of a mouse, view- 
ed by Mr. Derham with a microscope, 
seemed to be one single transparent tube, 
with a pith made up of fibrous substances, 
running in dark lines, in some hairs trans- 
versely, in others spirally. The darker 
medullary parts or lines, he observes, were 
no other than small fibres convolved round, 
and lying closer together than in the other 
parts of the hair; they run from the bottom 
to the top of the hair, and, he imagines, 
may serve to make a gentle evacuation of 
some humour out of the body : hence, the 
hair of hairy animals, this author suggests, 
may not only serve as a fence against cold, 
&c., but as an organ of insensible perspira- 
tion. Hair makes a very considerable arti- 
cle in commerce, especially since the mode 
of perukes has obtained. The hair of the 
growth of the northern countries, as Eng- 
land, &c. is valued much beyond that of 
the more southern ones, as Italy, Spain, the 
south parts of France, &c. The merit of 
good hair consists in its being well fed, and 
neither too coarse nor too slender; the big- 
ness rendering it less susceptible of the ar- 
tificial curl, and disposing it rather to friz- 
zle, and the smallness making its curl of too 
short duration. Its length should be about 
twenty-five inches ; the more it falls short 
of this, the less value it bears. 
The scarceness of grey and white hair, 
has put the dealers in that commodity upon 
the methods of reducing other colours to 
these. This is done by spreading the hair 
to bleach on the grass like linen, after first 
washing it out in a bleaching water : this 
ley, with the force of the sun and air, brings 
the hair to so perfect a whiteness, that the 
most experienced person may be deceived 
therein ; there being scarce any way of de- 
tecting the artifice, but by boiling and dry- 
ing it, which leaves the hair of the colour of 
a dead walnut-tree leaf. Hair, like wool, 
may be dyed of any colour. 
Hair which does not curl or buckle natu- 
rally, is brought to it by art, by first boil- 
ing, and then baking it, in the following 
manner : after having picked and sorted 
the hair, and disposed it in parcels accord- 
ing to lengths, they roll them up, and tie 
them tight down upon little cylindrical in- 
struments, either of wood or earthen ware, 
a quarter of an inch thick, and hollowed a 
little in the middle, called pipes ; in which 
state they are put in a pot over the fire, 
there to boil for about two hours. When 
taken out, they let them dry; and, when 
dried, they spread them on a sheet of brown 
paper, cover them with another, and thus 
send them to the pastry-cook, who, making 
a crust or coffin around them, of common 
paste,' sets them in an oven till the crust is 
about three-fourths baked. The end by 
which a hair grows to the head, is called 
the head of the hair; and the other, with 
which they begin to give the buckle, the 
point. Formerly the peruke-makers made 
no difference between the ends, but curled 
and wove them by either indifferently ; but 
this made them unable to give a fine buckle ; 
hair woven by the point never taking a 
right curl. 
Hair is also used in various other arts and 
manufactures : in particular, the hair of 
beavers, hares, conies, &c. is the principal 
matter whereof hats are made. Spread on 
the ground, and left to putrify on corn- 
lands, hair, as all other animal substances, 
viz. horns, hoofs, blood, &c. proves good 
manure. 
This, like every part of the animal sys- 
tem, has been chemically analysed, and has 
•been found to contain a large portion of ge- 
latine, which may be separated from it by 
