ENA 
germ; capsule opening on the side; seed 
one, arilled. There is but one species ; viz. 
E. sen-datum, Cape empleurum. This is a 
shrub, with wand-like, even branches ; 
leaves like those of a willow, alternate, 
subpetioled, linear-lanceolate, even above, 
beneath longitudinally wrinkled; peduncles 
few-flowered, lateral, much shorter than the 
leaves; flowers small, most of them mate; 
capsules usually solitary, incurved, w r ith a 
beak of the. same length. 
EMULSION, a milky looking fluid caus- 
ed by an imperfect combination of oil witii 
water by means of mucilage, gluten, &c. 
All oily farinaceous seeds, as nuts, almonds, 
linseed, &c. form an emulsion by trituration 
with water : yolk of egg, which is a natural 
compound of oil and albumen, makes a si- 
milar emulsion. 
ENAMELLING. Neri on Glass, with 
the notes of Merret and Kunckel, afford a 
variety of good receipts for making enamels, 
though much still remains to be done in this 
art. The art is indeed retarded by the con- 
siderable advantages the enameller derives 
from the discovery of any colour uncom- 
monly brilliant, clear, or hard. On this ac- 
count the artist naturally endeavours to 
keep his process a secret, as the source of 
private gain. The principal ingredients of 
enamel colours are, however, well known. 
There are two kinds of enamel ; the opaque 
and the transparent. Transparent enamels 
are usually rendered opaque by adding put- 
ty, or the white oxide of tip, to them. The 
basis of all enamels is therefore a perfectly 
transparent and fusible glass. The oxide 
of tin renders this a beautiful white, the 
perfection of which is greater when a small 
quantity of manganese is likewise added. If 
the oxide of tin be not sufficient to destroy 
the transparency of the mixture, it pro- 
duces a semi-opaque glass, resembling the. 
opal. 
Yellow enamel is formed by the addition 
of oxide of lead or antimony. Kunckel like- 
wise affirms that a beautiful yellow may be 
obtained from silver. 
Red enamel is formed by the oxide of 
gold, and also by that of iron. The former 
is the most beautiful, and stands the fire, 
which the latter does not. 
Oxide of copper affords a green, manga- 
nese a violet, cobalt a blue, and iron a very 
fine black. A mixture of these enamels 
produces a great variety of intermediate 
colours, according to their nature and pro- 
portion. In this branch of the art the co- 
loured enamels aie sometimes mixed with 
ENA 
each other, and sometimes the oxides are 
mixed before they are added to the vitrious 
bases. 
The enameller who is provided with a 
set of good colours is very far from being in 
a situation to practise the art, unless he be 
skilled in the methods of applying them, 
and the nature of the grounds upon which 
they are to be laid. Many of the me- 
tals are too fusible to be enamelled, and 
most of them are corroded by the action of 
the fused glass. For this reason none of the 
metals are used but gold, silver, and cop- 
per. Platina has indeed been used; but 
of its effects and habitudes with enamel 
very little can be said, for want of a suffi- 
cient number of experiments. 
Tiie purest gold, of 24 carats, is calculated 
to produce the best effect with enamel. 
1. Because it entirely preserves the metallic 
brilliancy, without undergoing any oxidation 
in the fire. 2. Being less fusible, it will 
admit of a more refractory, and consequently 
a harder and more beautiful enamel. It is 
not usual, however, to enamel on finer gold 
than 22 carats ; and the operation would be 
very defective, if a coarser kind than that 
of 18 carats were used. For in this case 
more alkali must be added to the enamel to 
render it more fusible, and this addition 
would, at the same time, render it softer and 
less brilliant. 
Rejecting all these exceptions, the follow- 
ing description may be taken, by way of 
example, of fixing a transparent blue enamel 
upon gold of 22 carats. 
The artist begins bis operation by break- 
ing bis enamel into small pieces in a steel 
mortar, and afterwards pulverizing it in a 
mortar of agate. He is careful to add wa- 
ter in this part of the process, which pre- 
vents the splinters of glass from flying about. 
There are no means of explaining the point 
at which the trituration ought to be given 
up, as this can be learned only by experi- 
ence. Some enamels require to be very 
finely triturated ; but others may be used 
in the form of a coarse powder. As soon as 
he apprehends that his enamel is sufficiently 
pounded, he washes it by agitation in very 
clear water, and pouring off the fluid as it 
becomes turbid. This process, which is 
made for carrying off dust and every other 
impurity from the enamel, is continued un- 
til the water comes off’ as clear as it was 
poured on. 
The workman puts his enamel thus pro, 
pared into a white earthen or china saucer, 
with water poured on it to the depth of 
