Effects of Poisons on Living Vegetables. 127 



3. With oil of tobacco. — Amaranthus and Zinea, 



These additional experiments, performed by a skillful practical 

 botanist, confirm the observations previously made : hence, we 

 are permitted to conclude, first. That the experiments detailed 

 by professor Marcaire, are erroneous. Second, That substances 

 which act as lethel poisons to animal life, are not so to vegetables. 



We cannot but admire the wisdom, order, and harmony of 

 creation ! fixed to the earth by immutable laws, plants and 

 flowers would have soon ceased to exist, had their susceptibilities, 

 like those of animals, rendered them liable to the agency of poi- 

 sons, to contact with which they are so much exposed. 



Pt. Harlan, M. D. 



We had the satisfaction of assisting, during the present month, 

 together with professor Del Rio, at a repetition of those curious 

 experiments on vegetable substances, with vegetable and mineral 

 poisons. They were conducted by Dr. Harlan, assisted by Dr. 

 Moore, in the garden of the Philadelphia Alms-house Infirmary, 

 and the results corresponded precisely with those obtained in 

 September, 1830. 



The plants to which the poisons were applied, were palma 

 christi, stramonium, nicotiana tobacum, balsamina impatiens, 

 brassica, geranium, and carduum benedict. 



The poisons used in the experiments, were ol. tabaci, oxyd. 

 arsenic, extr. stramonium, extr. cicuta, corros. sub. in sol., oL 

 terebinthi, and a strong solution of opium. 



Each of these poisons was separately introduced into the cir- 

 culation of individual plants, by incisions made in the stems, un- 

 der the leaves, and by similar, separate applications of them to 

 their roots ; by infusions, and by powder also, in the case of ar- 

 senic. In some instances the poisons were placed around the 

 roots only, viz. corros. sublimate, arsenic, sp. turpentine, and oil 

 of tobacco. 



In none of these instances was any of the plants poisoned. One of 

 the young geraniums faded, after constant impregnation, for three 

 days, of the earth about its roots, but this is evidently attributable 

 to its soil being rendered unfit for the support of vegetable life. 



We must therefore adhere to the reasonable opinion, that 

 plants have the property of segregating from the soil or atmo- 

 sphere, those principles which are proper for their healthy state, 

 and of rejecting those which are injurious to their organization. 



