208 
SELECTED ARTICLES. 
ART. XXXIV.— RESULTS OF EXPERIMENTS MADE UPON 
THE MILKY JUICE OF LETTUCE. {Lactma sativa, L., the 
variety termed Roman.) By M. * * *. 
The juice which I examined was collected in the month of 
July, when the temperature was 24 to 25 R., from stalks of 
the lettuce about to flower. It was of great purity and pos- 
sessed an oily consistence at the moment of exudation, it 
concreted rapidly, at the same time that it acquired a brownish 
tint. It exhibited an acid reaction. 
Five decigrammes of this juice, dried by exposure to the 
atmosphere, furnished seventeen centigrammes of residuum, 
or 34 per cent. This product, which, as is known, is very 
analogous to what is called Lactucarium by the English, 
occurs under the form of irregular fragments, reddish brown 
externally, whitish internally, not perceptibly attracting 
humidity from the atmosphere, taste very bitter, smell virose. 
The different experiments which I have made upon this 
juice have induced me to regard it as composed of : 
1. A bitter principle, soluble in water and alcohol, insoluble 
in ether, not precipitated by the salts of lead. 
2. Albumen. 
3. Caoutchouc. 
4. Wax. 
5. An acid of which I have not been able to determine the 
nature, on account of the small quantity of juice which I had 
at my command. 
6. Chloride of calcium. 
7. Phosphate of lime. 
8. Potassa. 
It may also be possible, that gum and acetic acid exist in it. 
Gum has been stated to be present by Shrader, as well as a 
peculiar resin, of which I have not detected any traces; but I 
have found gum in the extract of lettuce obtained by expres- 
sion, as also acetic acid and potassa. 
