DIF 
violent, opium must necessarily be had re- 
course to, but never otherwise. 
Wlien the sense of sinking in the sto- 
mach is distressing, and particularly when 
this symptom occurs with cardialgia, the 
best stimulus is the compound spirit of am- 
monia, in camphor mixture, or in some other 
light vehicle ; this is ranch less injurious to 
the digestive organs, than mther or any 
other strong spirituous preparation, or than 
aromatic confection, or any other spice in 
large quantity ; and it is frequently useful in 
conquering the patient’s habit of taking 
high-seasoned dishes : it is sometimes not 
only useful but necessary to be gradual in 
breaking this habit, and it is commonly 
best to allow a few glasses of generous wine, 
requesting the patient at the same time to 
avoid all spirituous liquor ; a little wine is 
often well applied-, as it stimulates him to 
take food which he would not otherwise 
touch, and enables him to digest it more 
easily. Here the diet cannot be too plain 
and simple : rice is one of the best vegeta- 
bles, whether in gruel or in a solid form, and 
should be duly intermixed with animal 
food, either roasted or boiled at the pa- 
tient’s option. 
Bath water in moderation, and with 
strict attention to the state of the bowels, 
often proves an excellent restorative. Soda 
water is one of the best beverages that can 
be prescribed. Much walking usually in- 
duces dropsy, and should therefore be 
avoided ; moderate exercise, however, is 
of high importance, and it may be varied 
with great advantage by riding on horse- 
back, in a carriage, and short excursions on 
the water. ‘ 
Tliere are several other diseases which 
are also dependent upon a vitiated state of 
the digestive organs, and are peculiarly the 
objects of dietetic medicine. But, in ge- 
neral, they will be found of less conse- 
quence, and more easily subdued : they 
will be characterised by the slighter symp- 
toms attendant upon those already noticed, 
and will yield to the common plan of medi- 
cal regimen prescribed for their cure. 
DIFFERENCES, in heraldy, certain 
additaments to coat armour, whereby some- 
thing is added or altered to distinguish 
younger families from the elder. 
Of these differences Sylvanus Morgan 
gives us nine ; viz. the label, for the first son ; 
the crescent, for the second ; the mullet, 
for the third; the martlet, for the fourth; 
the annulet, for the fifth ; the flower-de-lis, 
for tlte sixth ; the rose, for the seventh ; 
DIG 
the eight-foil, for the eighth ; and the cross- 
moline, for the ninth. 
Again, as the first differences are single 
for the sons of the first house or descent, 
the sons of the younger house are differed 
by combining or putting the said differences 
upon each other. As the first differences 
are the label, crescent, &c. for the first 
house, the difference for the second house 
is the label on a crescent for the first of 
that house ; for the third brotlier of the se- 
cond house, a mullet on a crescent, &c. 
DIFFERENTIAL calculus. See Cal- 
CULUS.- 
DIGESTER, an instrument to dissolve 
solid animal substances, in a manner some- 
what similar to that performed by the sto- 
mach. The vessel was invented by Papin : 
hence it is usually called “ Papin’s Diges- 
ter.” After putting meat into it, together 
with a sturicient quantity of water, a lid is 
closely screwed on, so as to admit no exter- 
nal air. By a moderate fire the meat will, 
in the course of six or eight minutes, be 
reduced to a perfect pulp : by augmenting 
the heat of the fire, or extending the time 
of digestion, the hardest bones may be con- 
verted into a jelly. To these machines there 
is also a safety valve, which should always 
be kept in good order; for if, by any 
means, it is put over the fire, and the valve 
incapable of opening, the most fatal conse- 
quences may happen from the immense 
power of confined steam. 
DIGESTION, in animal economy. An 
important distinction exists between ani- 
mals and vegetables, in the mode in which 
they receive their nourishment. Vegeta- 
bles are constantly absorbing matter from 
the soil ; it immediately passes into the sap 
vessels, and is soon changed by respiration 
and secretion. Animals, on the contrary, 
with very few exceptions, take in food at 
intervals, and retain it in their stomach for 
a considerable time, where it undergoes a 
chemical change, which constitutes the 
function of digestion, the first step in the 
general process by which animal matter is 
formed. See Physiology. 
Digestion, in chemistry, an effect pro- 
duced by the continued, soaking of a so- 
lid substance in a liquid, with the applica- 
tion of heat. 
DIGIT, DIGITUS, in astronomy, the 
twelfth part of the diameter of the sun or 
moon, is used to express the quantity of 
an eclipse. Thus an eclipse is said to be 
of six digits, when six of these parts are 
hid. 
LI 2 
