ABSORPTION OF ARSENIC BY PLANTS. 
711 
watered a small piece of grass and that died also, and the 
shoots of a rose-bush, which I dipped into the same solution, 
soon turned black, and at the end of two days was completely 
withered. These results being apparently quite opposed to 
the statement of Dr. Davy, 1 thought that it might be objected 
that the plants had not been transplanted long enough to 
afford a fair trial. I therefore watered with the same solution 
a broeoli plant which was growing in the garden very luxu¬ 
riantly, perhaps a foot high, and very strong. This was 
watered on the 17th Sept., and after ten hours it shared the 
same fate as the other plants. I continued to water this 
plant every other day, and on the sixth day very little of the 
plant was remaining. It appeared, as it were, burnt up, a 
section of the stem presenting a black morbid appearance. 
My next experiment was on three other broeoli plants grow¬ 
ing in the same piece of ground as the one just mentioned, 
and planted at the same time, and these I watered with solu¬ 
tions of different strengths. No. 1 was watered with a solu¬ 
tion made of 30 grains of arsenic and 60 oz. of water, and 
this solution was divided into six parts, and one part given 
every other day to the roots of the plant. No. 2 was treated 
with a solution made of 15 grains of arsenic and 60 oz. of 
water; and this also was divided into six portions as in the 
first case. In No. 3, a very dilute solution of 7J grains of 
arsenic to 60 oz. of water was applied. I consider, therefore, 
that No. 1 had 30 grains of arsenic, No. 2, 15 grains, and 
No. 3, 7 k) applied to their roots; and this I thought would 
be amply sufficient for the detection of arsenic if absorbed 
by them at all. The plants continued to look healthy, and 
as no sign of their having been poisoned was visible, I cut 
them off just above the ground, and examined them chemi¬ 
cally for arsenic. A section of the stem showed nothing 
uncommon, and after a very careful examination I failed to 
detect any trace of arsenic in either of these three plants. 
Under these circumstances, I cannot help doubting very 
much the correctness of the statement that plants will absorb 
arsenic at all; and even if they could, I see no ground for 
apprehension that they could derive it in any quantity worth 
noticing from any of the superphosphates now in general 
use; and I am greatly confirmed in this view of the case 
by the interesting and able remarks, by Mr. Sibson, in your 
last week’s paper, to the same effect.— Gardeners' Chronicle , 
October 3. 
