416 MEDICAL BOTANY. 



tuce at night ; and Celsus says " somno vero aptum est lactuca, maximaque 

 sestiva, cujus cauliculus jam lacte repletus est." The part now employed is 

 the inspissated juice or Lactucarium. This was employed by the ancients, 

 but its use was forgotten, until about the close of the last century, Dr. J. R. 

 Coxe again called the attention of the public to it, in a paper in the Transac- 

 tions of the American Philosophical Society, iv. 387 ; but little notice was 

 taken of his communication, until in 1810, Dr. Duncan of Edinburgh again 

 brought the subject before the medical profession, and detailed his experiments 

 with it, though he wholly neglected to notice the previous labours of Dr. Coxe. 

 It was now extensively used both in England and on the continent of Europe, 

 and has since been admitted as an officinal article in all pharmacopoeias. Two 

 kinds are employed : the true lactucarium, which is the inspissated juice ob- 

 tained by wounding the plant, permitting the exudation to concrete ; and the 

 thridace of most writers, which is the expressed juice evaporated to a due 

 consistence, and hence contains all the secretions of the plant that can be 

 forced out by pressure. The article used by Dr. Duncan differed from both 

 these, being a spirituous extract. 



Lactucarium, as found in the shops, is in roundish, hard masses, of a 

 brown colour, with a narcotic odour, and a bitter, unpleasant taste. Accord- 

 ing to Buchner {Pcreira, ii. 413), it contains an Odorous matter, Lactucin, 

 Gummy extractive, soft Resin-, Myricin, Gluten, &c. The lactucin or bitter 

 principle is probably the efficient constituent. There is no trace of morphia 

 to be detected. 



Medical Properties. — Lactucarium is anodyne and sedative, and may be 

 administered where opium is contra-indicated, either from idiosyncrasy, or 

 where there is much excitement of the system. It is not, however, as certain in 

 its effects as opium, but still forms a valuable addition to the class of seda- 

 tives, more especially, as from some experiments it appears to possess the 

 power of diminishing the quickness of the pulse, and at the same time in- 

 creasing its tone ; hence it is much prescribed in Germany in palpitations of 

 the heart. It also has some diuretic powers, and has been given with suc- 

 cess in dropsy; and as a calmant in coughs it is fully equal to opium. It is 

 but seldom used in this country, especially since the introduction of morphia 

 and its preparations. It is given in substance in doses of two to five grains, 

 and in tincture in those -of twenty drops to one drachm, which latter quantity 

 contains six grains of lactucarium. 



Another species, the L. virosa, or wild lettuce of Europe, is possessed of 

 the same properties, but affords nearly three times as much Lactucarium as 

 the cultivated species. No experiments have been made with the wild let- 

 tuce of this country, L. elongata, but as it abounds in a bitter milky juice, 

 and is common in all the States, it is worthy of attention. 



G-roup XXVI. — Campanales.. 



Order 62.— CAMPANULACEiE.— R. Brown. 



Calyx superior, usually 5-lobed, persistent. Corolla monopetalous, inserted on the top 

 of the calyx, usually 5-lobed, marccscent, regular, aestivation valvate. Stamens inserted 

 into the calyx, alternately with the lobes of the corolla, which they equal in number. 

 Anthers distinct, 2-celled. Pollen spherical. Ovary inferior, with 2 or more many-seeded 

 cells, opposite the stamens or alternate with them. Style simple, hairy. Stigma na- 

 ked, simple, or with as many lobes as there are cells. Fruit dry, crowned by the withered 

 calyx and corolla, dehiscing by lateral apertures or by apicial valves, always loculicidal. 



