398 COMPOSITiE. 



on the Thaya, where about 35 kilogrammes are annually produced. It 

 is in fine tears of vigorous smell. 



We are unacquainted with Russian lactucarium, which has been 

 quoted at a very high price in some continental lists. 



Chemical Composition — Lactucarium is a mixture of very diiSerent 

 organic substances, together with 8 to 10 per cent, of inorganic matter. 

 It is not completely taken up by any solvent, and when heated merely 

 softens but does not melt. Nearly half the weight of lactucarium con- 

 sists of a substance called Lactucerin or Lactucon, which in our opinion 

 is closely allied to if not identical with similar substances occurring in 

 numerous milky juices. Lactucerin as afforded by the drug under ex- 

 amination is probably a mixture of several bodies. It may be obtained 

 by exhausting lactucarium with boiling alcohol sp. gr. 0880 ; it is 

 deposited in crystals, which when duly purified have the form of slender 

 colourless, microscopic needles. Lactucerin is an inodorous, tasteless 

 substance, insoluble in water, but dissolving in ether and in oils both 

 fixed and volatile, not quite so readily either in benzol, or in bisulphide 

 of carbon. We found it to melt at 232° C. and to agree with the 

 formula C^'H'^O ; Franchimont (1879) assigns to it the formula e*H="0, 

 melting point 296°. 



Euphorbon (see Euphorbium), echicerin (see Cortex Alstoniae), 

 taraxacerin (p. 394), the cynanchol, C^*ff*0, extracted in 1875 by 

 Buttleroff from Cynanchum acutwrn L., are remarkably analogous to 

 lactucerin. 



In the lactucarium of Zell, we further met with a large amount of a 

 substance which is readily soluble in bisulphide of carbon. It is an 

 amorphous mass, melting below 100°, separating from alcohol as a 

 syrupy mass. 



Cold alcohol, as well as boiling water, takes out of lactucarium about 

 O'S per cent, of a crystallizable bitter substance, Lactucin, C"ff ^O^H'O, 

 which although it reduces alkaline cupric tartrate, is not a glucoside. 

 It may be best obtained by means of dialyse. Lactucin forms white 

 pearly scales, readily soluble in acetic acid, but insoluble in ether. It 

 loses its bitterness when treated with an alkali. 



From the mother-liquors that have yielded lactucin, Ludwig, in 

 1847, obtained Ladtocic Add, as an amorphous light yellow mass, 

 becoming crystalline after long standing. Lastly lactucarium has 

 further afforded in small quantity an amorphous substance named 

 Lactucopicririy C^*H"0"\ apparently produced from lactucin by oxida- 

 tion ; it is stated by Kromayer (1862) to be soluble in water or alcohol, 

 and to be very bitter. 



Of the widely diffused constituents of plants, lactucarium contains 

 caoutchouc (40-50 per cent.), gum, oxalic, citric, malic and succinic acids, 

 sugar, mannite, and asparagin, together with potassium, calcium and 

 magnesium salts of nitric and phosphoric acids. We obtained crystals 

 of nitrate of potassium by concentrating the aqueous decoction of 

 lactucarium. On distillation with water, a volatile oil having the odour 

 of lactucarium passes over in very small quantity. 



Uses — The soporific powers universally ascribed in ancient times 

 to the lettuce are supposed to exist in a concentrated form in lactu- 

 carium. Yet numerous experiments have failed to show that this 



