96 



ON THE GENERAL ANALOGY OF 



the cascarilla bark and castor oil are obtained from plants poisonous in some 

 part or other. 



The amyris, in one of its species, offers the balm-of-gilead tree ; in another, 

 the g-um-elemi tree ; and in a third,* the poison-ash, th?tt secretes a liquid 

 gum as black as ink It is from a fourth species of this genus, I will just ob- 

 serve as I pass along, in order the more completely to familiarize it to us, 

 that we obtain that beautiful plant which, under the name of rose-wood,t is 

 now so great a favourite in our drawing-rooms. 



The acacia nilotica,X gum-arabic tree, is a rich instance in proof of the 

 same observation. Its root throws forth a fluid that smells as offensively 

 as asafoetida ; the juice of its stem is severely sour and astringent ; the se 

 comments of its cutis exude a sweet, saccharine, nutritive gum, the common 

 gum-arabic of the shops, and its flowers diffuse a highly fragrant and regal- 

 ing odour. So the arenga palm produces sugar, an excellent sago, and a 

 poisonous juice that even irritates the skin. 



But perhaps the laurus, as a genus, offers us the most extensive variety of 

 substances of different qualities. This elegant plant, in one of its species, 

 gives us the cinnamon tree in another, the cassia, or wild cinnamon ;|| in 

 a third, the camphor tree ;TP in a fourth, the alligator-pear;** in a fifth, the 

 sassafras ;tt in a sixth, a sort of gum-benjamin,JJ though not the real gum- 

 benjamin, which is a styrax ; while in a seventh, the L. caustica, it exhibits 

 a tree with a sap as poisonous as that of the manchineel. 



And truly extraordinary is it, and highly worthy of notice, that various 

 plants, or juices of plants, which are fatally poisonous to some animals, may 

 not only be eaten with impunity by others, but will afford them a sound and 

 wholesome nutriment. How numerous are the insect tribes that feed and 

 fatten on all the species of euphorbia, or noxious spurge ! The dhanesa, or 

 Indian buceros, feeds to excess on the nux vomica ; the land-crab^^^ on the 

 berries of the hippomane or manchineel-tree, and the loxia (grossbeak) of the 

 Bahamas on the fruit of the amyris toxifera, or poison-ash. |||| The leaves of 

 the kalmia latifolia are feasted on by the deer and the round-horned elk, but 

 are mortally poisonous to sheep, to horned cattle, to horses, and to man. 

 The bee extracts honey without injury from its nectary, but the adventurer 

 who partakes of that honey after it is deposited in the hive-cells falls a vic- 

 tim to his repast. 



There are some tribes of animals that exfoliate their cuticle annually, such 

 as grasshoppers, spiders, several species of crabs and serpents. Among vege- 

 tables we meet with a similar variation from the common rule in the shrubby 

 cinquefoil,]PF indigenous to Yorkshire, and the plane-tree of the West In- 

 dies,*** which most readers know sends forth every spring new colonies by 

 means of runners, as we usually denominate them, in every direction, that, 

 shortly after they have obtained a settlement for themselves, break off all 

 connexion with the parent stock. 



Among animals, some are locomotive or migratory, and others sta- 

 tionary or permanent ; the same variety is to be traced among vegetables. 

 Unquestionably the greater number of animals are of the migratory kind, yet 



* A. toocifera. f A. halsamifera. % Mimosa nilotica, Linn. 



§ L. cinnamomium, . || L. cassia. IF L. camphora. 



** L.persea. it l^- sassafras. tt ^- benzoin. Cancer ruricola. 



II !l See on this subject the following curious papers in the Swedish Amcenitates Academicae, vol. ii. art. 

 25, par Sueisens, by N. L. Flesselgren. The same subject continued by G. P. Tengmalon, Amcen. Acad, 

 vol. X. art. X. Usus Historiae Naturalis, by M. Aphonin, art. 147. lb. in respect to birds, entitled Esca 

 Avium domesticarum, by P. Holmbergen, p. 481, art. 163. 



It is also well worthy of remark, that various herbaceous plants which spring up among others that are 

 esculent, yet are rejected by cattle when offered alone, give a higher relish and even salubrity to the fodder 

 with which they are intermixed. This, as Sir J. E. Smith has admirably observed, is particularly the case 

 with the grasses. "As man cannot live on tasteless unmixed flour alone, so neither can cattle in general 

 be supported by mere grass, without the addition of various plants in themselves too acid, bitter, salt, or 

 narcotic to be eaten unmixed. Spices and a portion of animal food supply us with the requisite stimuhis 

 or additional nutriment, as the ranun(;ulus tribes, and many others, season the pasturage and fodder of cat 

 tie. — Engl. Flora, vol. i. 



TTIf Potentilla/mficosa. •** Platanus ocddmtalis. 



