May G, 1871.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
8 S3 
So beautifully is the seed balanced, that the 
slightest breeze carries it away like a miniature 
balloon. 
Lactuca virosa (Linn.). 
This plant does not occur very plentifully near 
Bristol, but may be gathered on St. Vincent’s rocks 
and at Leigh. Its usual height is about two feet, 
and it never attains the size frequently seen in the 
south-eastern parts of England. 
Bentham considers Lactuca virosa to bo a Va¬ 
riety of L. Scariola, only differing by the leaves 
being dess glaucous and broader in form. If this 
opinion be correct, it would reconcile Dr. Sibtliorp’s 
objection to Sprengel’s assertion, that Lactuca virosa 
was the 6piba% aypla of Dioscorides. The lettuce is 
common in Greece and Ital} r , and was undoubtedly 
used by the Romans as a salad and medicine. Ho¬ 
race (Sat. 2.8) speaks of its use as a provocative to 
the appetite:— 
“ Rapula, lactucae, radices; qualia lassum 
Perveliunt stomachura.” 
In another place (Sat. 2.4), he says that lettuces 
are indigestible things for the habitual drinker, when 
suffering from dyspepsia and acidity :—■ 
Nam lactuca innatat acri 
Post vinum stomaclio.” 
mixed until chlorophyll. One hundredweight of the 
plant will produce from four to five pounds of ex¬ 
tract. 
The proper time for gathering the lettuce for 
pharmaceutical use is about the middle of the time 
of inflorescence. 
{To be continued.) 
DISTILLATION IN PARTIAL VACUO. 
The vessel in which the liquid is to be distilled 
may be either a flask or a tubulated retort, with a 
narrow neck fitting into a large, tubulated globe. 
Bend a glass tube twice at right angles, pass the 
short leg through the tiibulus of the globe, and 
the long leg by means of an india-rubber cork into 
a wide tube holding about 100 c.c., and terminating 
in a very narrow tube at least 30 in. long; the 
lower end of tliis long tube to dip into a mercury 
trough. 
Fit a bent tube into the flask or tubulus of the re¬ 
tort, and draw it out at a point outside the retort; 
attach a carbonic acid apparatus to this tube, and 
pass carbonic acid through the apparatus to expel 
( all atmospheric air, or until the gas escaping from 
! the long tube at the other end is completely absorbed 
by a solution of caustic potash. Now seal the tube 
by which the carbonic acid entered, at the narrow 
The lettuce owes its medicinal virtues to the pre¬ 
sence of lactucarium, or lettuce opium, a mild nar¬ 
cotic, and, like its poppy congener, is a compound 
of various principles. Its compo sition appears to 
be,— 
Lactucone. 
Lactucm and Lactucic 
Acid. 
Caoutchouc . . . 
Albuminous substance 
Mannite .... 
Oxalic Acid . . . 
Resin, moisture, etc. 
Ash. 
48-05 
10-61 
4-70 
7-33 
2-05 
1-00 
14-40 
4-30 
100-00 
Lactucone 
(C, 0 H 61 O 3 ) is 
tained from lactucarium by boil¬ 
ing alcohol, when it forms colour¬ 
less, insipid crystals, which melt 
between 150° and 160°. They are 
insoluble in water, but readily so 
in alcohol, ether and oil, 
Lactucin (C 22 H iS 0 3 ) is a yel¬ 
lowish, bitter, cr}'stalline substance, 
which is not very soluble in ether, 
but more so in alcohol and acetic 
acid. 
Lactucic acid is a vellow amor- 
V 
pilous substance, obtained by the 
action of dilute sulphuric acid on 
lactucarium. Like mannite and 
glucose, it reduces cupric sulphate. 
The Lactuca sativa, or garden 
lettuce, contains lactucarium, but 
in much less quantity. Schultz ^__ 
says a plant of L. sativa will yield 17 grains, while j point, pour about 100 c.c. of caustic potash lye on 
one of L. virosa will yield 50 grains. the mercury, and lower the trough until the tube 
Extractum lactucre consists chiefly of lactucarium dips into the lye. 
