DEL 
lead and tin are oxyded together with a 
strong fire ; and the sand is- also to be made 
into a frit with the salt or ashes. The 
whole is then to be well mixed and ground 
together. The matter is then to be placed 
under the furnace, where it is melted and 
vitrified during the baking of the ware. 
It is next to be ground in a mill, and ap- 
plied as above directed. 
Concerning the earth of which the ware 
is made, pure clay is not a proper material 
when used alone. Different kinds of earth 
mixed together are found to succeed bet- 
ter ; pieces of ware made of clay alone are 
found to require too much time to dry, 
and they crack and lose their form, unless 
they are made exceedingly thick; an ad- 
dition of marie diminishes the contraction 
of the clay, renders it less compact, and 
allows the water to escape without altering 
the form of the ware in drying. It affords 
also a better ground for the enamel, which 
appears more glossy and white than when 
laid on clay alone. The kinds of clay 
which are chiefly used in the composition 
of delft-ware, are tlie blue and green. A 
mixture of blue clay and marie would not 
be sufficiently solid, and w'ould be apt to 
scale, unless it were exposed to a fire more 
intense than what is commonly used for 
the burning of delft -ware. To give a 
greater solidity, some red clay is added; 
which, on account of its ferruginous matter, 
possesses the requisite binding quality. 
The proportions of these ingredients vai-y 
in different works, according to the different 
qualities of the earths employed. Three 
parts of blue clay, two parts of red clay, 
and five parts of marie, form the composi- 
tion used in several manufaetories. See 
Enamel. 
DELIMA, in botany, a genus of the 
Polyandria Monogynia class and order. 
Natural order of Rosaceae, Jussieu. Essen- 
tial character: calyx five-leaved; corolla 
none ; berry with two seeds. There is but 
one species, viz. D. sarmentosa, a native 
of Ceylon. 
DELIQUESCENCE, in chemistry, a 
term to certain saline bodies that have be- 
come moist or liquid, by means of the water 
which they absorb from the atmosphere, in 
consequence of their great attraction to 
water. When the salt has, by exposure to 
air, become so far deliquesced as to be in 
a liquid state, it is said to be in the state 
of deliquium. Hence alkali, reduced by 
this means to a liquid state, was formerly 
denominated oil of tartar per deliquium. 
DEL 
DELIRIUM, in medicine, the produc- 
tion of ideas not answerable to external 
causes, from an internal indisposition of tlie 
brain, attended with a wrong judgment 
following from these ideas, and an affection 
of the mind and motion of the body ac- 
cordingly : and from these increased through 
various degrees, either alone or joined to- 
gether, vaiious kinds of deliria are pro- 
duced. 
DELIVERY, child-birth. See Mid- 
wifery. 
DELPHINUM, in botany, larkspur, a 
genus of the Polyandria Trigynia class and 
order. Natural order of Multisilique. Ra- 
nunculacese, Jussieu. Essential character : 
calyx none ; petals five ; nectary cloven, 
produced into a horn behind ; siliques three 
or one. There are eleven species. These 
are mostly hardy annuals or perennials. The 
lower leaves digitate or palmate ; the upper 
less divided, and sometimes even entire. 
The flowers are in loose panicles at the ends 
of tlie stem and branches, of various colours, 
but chiefly blue. 
DELPHINUS, the dolphin, in natural 
history, a genus of Mammalia of the order 
Cete. Generic character: teeth in each 
jaw ; spiracle on the head. Shaw enumer- 
ates six species, and Gmelin four. C. pho- 
caena, or the porpesse, is the most abundant 
of cetaceous animals, and is found particu- 
larly in the European seas, whence it often 
advances very nearly to the mouths of con- 
siderable rivers. Its general length is from 
five to eight feet. Porpesses are gre- 
garious, and frequently seen frolicking on 
the water, and playing their uncouth gam- 
bols, more especially in boisterous and tem- 
pestuous weather. They feed principally 
on smaller fishes, and pursue the shoals of 
herrings and mackrel with apparently un- 
wearied vigour and insatiable appetite. 
They are covered immediately under the 
skin with a fatty substance of considerable 
thickness, and which produces a large quan- 
tity of oil. The porpesse was formerly con- 
sidered, not merely as eatable, but as a 
species of luxury, being served up at noble 
and royal tables. Sucli, however, are the 
revolutions of taste, that by the least fiisti- 
dious appetite this food is at present decid- 
edly rejected. 
D. delphis, or the dolphin, has the same 
geneml habits and appearance with ffie pre- 
ceding, but is considerably longer, measur- 
ing occasionally even ten feet. It abounds 
both in the Pacific and European Se^, and 
its appearance is in general preliminary to 
