398 | HE. E. Free 195 
SYMPTOMS OF POISONING BY CERTAIN ELEMENTS, 
IN PELARGONIUM AND OTHER PLANTS 
By E. HE. Freres 
In connection with other experiments on the effects of pois- 
onous elements on plants, qualitative tests have been made 
of the symptoms of poisoning exhibited by the common cul- 
tivated geranium (Pelargonium zonale) and by several other 
plants, under the action of certain poisonous elements. The 
plants were grown in soil under ordinary greenhouse condi- 
tions. The poisons were applied by pouring the proper solu- 
tions on the soil when the latter was sufficiently dry to 
absorb and retain all of the added solution. Seven elements 
were applied to Pelargonium in five concentrations each. 
These were the following. Concentrations are in parts of the 
poisonous element per million parts of soil by weight. 
Concentrations 
p. p. m. 
Arsenic, as trioxide (As,0,).............. 2 to 500 
Boron, as borax (Na,B,0;)..............- 2 to 500 
Copper, as sulphate (CuSO,)...........-. 4 to 1000 
Iron, as ferrous sulphate (FeSQ,)......... 20 to 5000 
Lead, as nitrate (Pb(NO;)2)...-.---..-+-- 4 to 1000 
Manganese, as sulphate (MnSO,).......... 8 to 2000 
Zine, as sulphate (ZnSO,).........-.---:- 8 to 2000 
In addition to these seven elements the following were ap- 
plied in one concentration only, namely 500 parts per mil- 
lion:—barium, as chloride (BaCl,) ; bromine, as potassium 
bromide (KBr) ; cobalt, as sulphate (CoSO,) ; chromium, as 
potassium chromate (K,CrO,) ; iodine, as potassium iodide 
(KI) ; lithium, as sulphate (Li,SO,) ; mercury, as mercuric 
chloride (HgCl,); nickel, as sulphate (NiSO,); silver, as 
nitrate (AgNO,) ; uranium, as uranyl nitrate (U0,(NO,).2) 5 
and vanadium, as chloride (VCl,). All of these elements 
except iron were applied to Impatiens sultam, Coleus blumet 
