NAI 
Jyx none ; corolla none ; pistil one ; capsule 
ovate ; one-celled. Tliere is but one species, 
viz. N. marina, which, according to Jussieu, 
has three whorled siieatliing leaves, the 
flowers axillary, sessile ; the lihnnent in the 
male flowers long, witli a four-valved an- 
ther, which is the four-cleft corolla of Lin- 
naeus ; in the female flowers two stigmas, 
and one nut, or four seeds. Native of the 
sea coast of Europe ; in the canal between 
Pisa and Leghorn ; and in the Rhine, near 
Basle. 
NAIL. See Anatomy. 
The nails have been chemically examin- 
ed, and are found to be composed chiefly of 
a membranous substance, which possesses 
the properties of coagulated albumen. They 
contain also a little phosphate of lime. 
Water softens but does not dissolve them. 
They are readily dissolved and decomposed 
by concentrated acids and alkalies. It is 
pretty certain that they arc composed of the 
same substances as Horn, which see. Under 
the head of nails must be comprehended 
the talons and claws of the inferior animals, 
and likewise their hoofs, which differ in no 
respect from horn. 
Nails, in building, &c. small spikes of 
iron, brass. Sec. which being driven into 
wood, serve to bind several pieces together, 
or to fasten something upon them. The 
several sorts of nails are very numerous : 
as 1. Back and bottom nails ; which are 
made with flat shanks to hold fast, and not 
open the wood. 2. Clamp-nails, for fasten- 
ing the clamps in buildings, &c. 3. Clasp- 
nails, whose heads clasping and sticking into 
the wood, render the W'ork smooth, so as to 
admit a plane over it. 4. Clench -nails, used 
by boat and barge builders, and proper for 
any boarded buildings that are to be taken 
down, because they will drive without split- 
ting the M'ood, and draw without breaking ; 
of these there are many sorts. 5. Clout- 
nails, used for nailing on clouts to axle-trees. 
6. Deck-nails, for fastening of decks in 
ships, doubling of shipping, and floors laid 
with planks. 7. Dog-nails, for fastening 
hinges on doors, Sec. ' 8. Flat-points, much 
used in shipping, and are proper where 
there is occasion to draw and hold fast, and 
no convcniency of clenching. 9. Jobent- 
nails, for nailing thin plates of iron to wood, 
as small hinges on cupboard-doors, &c. 10, 
Lead-nails, for nailing lead, leather, and 
canvass, tohard wood. 11. Port-nails, for 
palling hinges to the ports of ships. 12. 
Pound-nails, which are four-square, and are 
much used in Essex, Norfolk, apd Suffolk, 
Nam 
and scarcely any where else, except for pall- 
ing. 13. Ribbing-nails, principally used in 
ship building, for fastening the ribs of ships 
in their places. 14. Rose-nails, which are 
drawn four-square in the shank, and com- 
monly in a round tool, as all common two- 
penny nails are ; in some countries all the 
larger sort of nails are made of this shape. 
15. Rother-nails, which have a full head, 
and are chiefly used in fastening rother-iruns 
to ships. 16. Round head nails, for fasten- 
ing on hinges, or for any other use where a 
neat head is required ; these are of several 
sorts. 17. Scupper nails, which have a broad 
head, and are used for fastening leather and 
canvass to wood. 18. Sharp-nails, these 
have sharp points and flat shanks, and are 
much used, especially in the West Indies, 
for nailing soft wood. 19. Sheathing-nails, 
for fastening sheathing-boards to ships. 20. 
Square-nails, which are used for hard wood, 
and nailing up wall fruit. 21. Tacks, the 
smallest of which serve to fasten paper to 
wood ; the middling for wool-cards, &c. 
and the larger for upholsterers and pumps. 
Nails are said to be toughened when too 
brittle, by heating them in a fire-shovel, 
and putting some tallow or grease among 
them. 
NAIS, in natural history, a genus of the 
Vermes Mollusca class and order. Body 
creeping, long, linear, pellucid, depressed ; 
peduncles, or feet, with small bristles on 
each side. There are ten species; N. digi- 
lata, has single lateral bristles; tail laciniate. 
It is found in stagnant waters, or the sandy 
sediment of rivers, with its head attached to 
the stalk of aquatic plants. It is not half an 
inch long; 
NAISSANT, in heraldry, is applied to 
any animal issuing out of the midst of some 
ordinary, and showing only his head, shoul- 
ders, fore-feet, and legs, with the. tip of his 
tail, the rest of his body being hid in the 
shield, or some charge upon it ; in which it 
differs from issuant, which denotes a living 
creature ari.sing out of the bottom of any 
ordinary or charge. 
NAKED, in architecture, is the surface 
or plain from whence the project ores arise, 
or w'liich serves as a ground to the projec- 
tures. Thus, w'esay the foliages of a capital 
ought to answer to the naked of a column, 
and that a pilaster ought to exceed toe na- 
ked of tlie wall by so many inches. 
NAMA, in botany, a genus of tie Pen- 
tandria Digynia class andordei. .Natural 
order of Sncculentae. Convolvuli, Jussieu. 
Essential character : calyx five-leaved; c.o- 
