160 LACTUCA VIROSA 



The milky juice when fresh reddens litmus paper, and is 

 coagulated both by acids and alcohol. The more important con- 

 stituents are doubtless those contained in Lactucarium, namely, 

 lactucerin or lactucone, lactucin, and lactucic acid ; these sub- 

 stances are described under the head of Lactucarium in our 

 article on " Lactuca sativa." The juice also contains a small 

 quantity of a volatile oil, to which its odour is due, albumen, 

 resin, and several salts. 



Medical Properties and Uses. This plant has long had a 

 reputation for narcotic properties, but the experiments of 

 Dr. Garrod, who gave lactucarium which is commonly reputed 

 to be the most active preparation of the plant in doses of thirty 

 grains and more, repeated every four hours, without observing 

 any very marked narcotic effects from its administration, clearly 

 prove that its powers, if any, must be very slight indeed. The 

 official extract is, however, sometimes given as a mild hypnotic 

 where the use of opium is objectionable, to procure sleep, allay 

 cough, &c. It is also said to be slightly laxative, antispasmodic, 

 and diuretic ; and has been employed more especially in Germany, 

 in dropsy. But in the treatment of dropsy, lettuce has been 

 generally combined with squill, digitalis, or some other well- 

 known diuretic, hence it is probable that the observed effect in 

 such cases is essentially due to the latter drugs. It has also been 

 used as a remedy in palpitation of the heart, in intermittent fever, 

 and in other cases, but although it was formerly highly spoken of 

 by practitioners, it is now regarded as useless in such cases. 



Per. Mat. Med., vol. ii, pt. 2, p. 36 ; Pharmacographia, p. 354 ; 

 U. S. Disp., by W. & B., pp. 517 & 521 ; Garr., Mat. Med., 

 p. 296; Woodville's Med. Bot., Supplement (1794), p. 100; 

 Steph. & Church., Med. Bot., by Burnett, vol. i, pi. 12; 

 Buchner's Repertorium (1847), 8. 



DESCRIPTION OF PLATE. 



Drawn from a specimen grown in Chelsea Garden. 1. The flowering plant 

 (much reduced). 2*. A branch with flowers. 3. A head. 4. The same in 

 section. 5. A single flower. 6. Portion of a hair of the pappus. 7. Anther. 

 8. Style. 9. Head of fruit. 10, 11. A single fruit. 12. Vertical, and 13. 

 Horizontal section of the same. (39 & 1113 enlarged.) 



