192 Miscellaneous Intelligence. 



ments were generally made with plants of the kidney bean (pha- 

 seolus vulgaris), and a comparison was always made with a plant 

 watered with spring-water. 



Metallic Poisons. Arsenic — A vessel containing two or three 

 bean plants, each with five or six leaves, was watered with two 

 ounces of water« containing twelve grains of oxide of arsenic 

 in solution. At the end of from twenty-four to thirty-six hours, 

 the plants had faded, the leaves drooped, and had even begun to 

 turn yellow ; the roots remained fresh, and appeared to be living. 

 Attempts to restore the plants after twelve or eighteen hours, by 

 abundant watering, failed to recover them. The leaves and stem 

 of the dead plant put into water gave, upon chemical examination, 

 traces of arsenic. 



A branch of a rose-tree, including a flower, was gathered just as 

 the rose began to blow ; the stem was put into a vessel containing 

 a solution of six grains of oxide of arsenic in one ounce of water, 

 on the 31st of March. On the 1st of April, the external petals 

 had become flaccid and slightly purple, and the leaves began to 

 droop ; 10 grains of water, or 0.12 of a grain of arsenic, had been 

 absorbed in twenty-four hours. On the 3rd April, the petals were 

 more flabby and faded, their colour deep purple and spotted, the 

 odour gone, and the leaves faded. During the last twenty-four 

 hours it had absorbed four grains of liquid. On the morrow the 

 branch was quite dead, and there was no further absorption. Only 

 a fifth of a grain of oxide of arsenic had been introduced. Arsenic 

 was found, by chemical examination, in the leaves and flower. 

 Similar stems placed in pure water had, after five days, the roses 

 fully expanded, the leaves fresh and green, and had absorbed 

 each, per day, 1 5 grains of water. 



On June 1, a slit of 1 j inch in length was made in the stem of 

 a lilac-tree, the branch being about an inch in diameter. The slit 

 extended to the pith. Fifteen or twenty grains of moistened oxide 

 of arsenic was introduced, the cut was closed, and the stem re- 

 tained in its natural position by osier-ties. On the 8th, the leaves 

 began to roll up at the extremity ; on the 15th, they had faded 

 and doubled up lengthwise, and the branches began to get dry ; 

 on the 28th, the branches were dry ; and in the second week of 

 July, the whole of the stem was dry, and the tree itself dead. 

 Other trees similarly cut, but without having had poison intro- 

 duced, suffered no kind of injury. 



On the side of the poisoned lilac was another, the trunk of 

 which joined the first a little above the earth. This tree became 

 entirely dry, and with similar phenomena, in about fifteen days 

 after the first. In another experiment, arsenic was put under the 

 bark of a lilac-tree ; in fifteen days, the two nearest principal 

 branches were dead and dry ; the rest did not suffer. 



Mercury, — Two or three bean-plants, growing in a pot, were 



