1899 | TOXIC EFFECT OF DELETERIOUS AGENTS 395 
Aspergillus and GEdocephalum also grew and fruited, but the cul- 
tures were much behind the checks. Penicillium was inhibited 
by = but was not killed by the saturated solution. Botrytis 
28 
was also inhibited by = and was killed by - That the solu- 
tion used was completely saturated was shown by the appearance 
of numerous microscopic crystals in some of the hanging-drops 
which were exposed for a few moments to the air, the evapora- 
tion from the culture medium causing some of the strychnin to 
crystallize out. The molds, however, continued to thrive in these 
cultures, their hyphe growing among the crystals. 
Of its effect on plants in general we have few data. Daven- 
port (’97) mentions that it kills the protoplasm of Drosera 
tentacles, and hinders the development of peas, corn, and lupines. 
The injurious concentrations, however, are not mentioned. 
Much interesting work has been done on Protozoa (Schiirmayer 
-'90) by various workers. The results of these studies as well as 
those presented here for the molds are in harmony with the 
theory of Loew (’93) that the action of alkaloids is chiefly con- 
fined to the plasma of the ganglion cells. Fungi and bacteria 
having no differentiation of nerve protoplasm are practically 
unharmed by this agent. 
Potassium iodid, bromid, and chlorid—These salts proved to 
have a very low toxic value. A complete series of cultures with 
the five molds was made up with the iodid only. Its coeffi- 
cients were determined to be 384, 2457, and 4915. 4 inhibited 
all except Aspergillus, — was fatal to all except Penicillium. 
As the potassium salts of the haloid acids are all quite highly 
lonized, an attempt was made to determine the relative toxic 
Properties of the zonic halogen elements. Aspergillus and CEdo- 
ephalum were used. To these molds ionic I proved doubly 
toxic as compared with Cl. Br occupied an intermediate post 
‘ion, being very slightly more toxic than ionic Cl. 
Sodium salicylate GyH ere we 24, 162,182, Tt was 
