626 CONSERVATIVE ORGANS. [LECT. XI. 



Berry, Arbutus uvce Ursi; almost the whole of 

 the genus Sumach, Rhus; the Tea, Thea; and 

 many other genera: and emetic in Asarabacca, 

 Asarum Europceum, &c. The purgative proper- 

 ties of the leaves of Senna, Cassia senna, and 

 of Hedge Hyssop, Gratiola officinalis ; and the 

 diaphoretic of Sage, Salvia officinalis, are well 

 known. The secretions of some leaves are so acrid 

 as to inflame and blister the skin when applied 

 to it; as those of many of the species of the 

 genus Ranunculus*; and of Savine, Juniperus 

 Sabina: on the other hand, some leaves, as those 

 of Marsh Mallow, Althea officinalis, and of Com- 

 mon Mallow, Malva sylvesiris, afford bland mu- 

 cilages; others, as those of Sorrel, Rumex acetosa, 

 and of Wood-Sorrel, Oxalis acetosella, contain 

 cooling acids: and some again, as those of the 

 Mints, Menthce; Balm, Melissa officinalis; Rue, 

 Ruta graveolens; the Cajuputi tree, Melaleuca 

 Leucadendron, &c. secrete essential oils, which 

 rouse and stimulate the animal system when taken 

 into the stomach, or even when applied to the 

 skin. As food, men employ a great variety of 

 leaves, which yield a bland fecula and saccharine 



* The leaves of R.jlammula are used for raising a blister 

 in the Hebrides. They are chopped and rubbed between hot 

 stones immediately before being applied ; and generally raise a 

 blister in an hour and a half. The leaves of R. sceleratus have 

 the same effect ; but often occasion an irritable sore, which 

 cannot readily be healed. 



