1914] Ross Alken Gortner and Arthur M. Banta 363 



Experiments with i-2-3-tri-hydroxy benzene (Pyrogal- 

 lol). Pyrogallol in a conc. of 0.005 percent or greater caused the 

 death of all amphibian eggs tested within 24 hr. The sei. assumed 

 a brown color, its depth depending on the conc. of the drug. The 

 eggs were also stained a brownish tint. 



Experiments with 1-3-5-TRi-HYDROXY benzene (Phloro- 

 glucinol). Phloroglucinol is readily acted on by light when in 

 sol., the colorless sol. becoming a brownish orange. This orange 

 sol. is intensely toxic. From the position of the hydroxyl groups we 

 expected to find that phloroglucinol had a toxicity as great or greater 

 than that of resorcinol. In a series of 20 experiments with Spelerpes 

 eggs and larvae and in a large number of tests using eggs and em- 

 bryos of both frogs and other Salamanders, we have found, how- 

 ever, that, if the sol. is not exposed to the action of light, the toxic- 

 ity of a sol. of a conc. as great as 0.05 percent., and, in the feW 

 instances tested, of as great a conc. as 0.5 percent, is almost negli- 

 gible. In conc. of 0.025 per cent, on the contrary, there is a slight 

 acceleration of pigmentation and probably of general development, 

 indicating a stimulating instead of a toxic effect. Even Daphnia, 

 which is unusually sensitive to an unfavorable medium, seem to live 

 well in this conc. of phloroglucinol. 



Experiments with a- and /S-naphthol^ cl- and /?-naphthyl- 



AMINE, />-AMIN0 PHENOL, /»-PHENYLENEDIAMINE, DI-AMINO PHE- 

 NOL (aMINO CROUPS?), AND M0N0-METHYL-/)-AMIN0-m-CRES0L. 



The behavior of these Compounds is so similar that they may be 

 classed together, The first four Compounds, when used in conc. of 

 0.005 percent or greater, kill developing eggs within a few hours. 

 With ct-naphthol and ot-naphthylamine the membranes of Amblystoma 

 eggs are stained a deep magenta. The other Compounds were tested 

 in only one conc, i. e., o.i percent; they all caused the death of the 

 eggs in a very short time. It may be of interest to note that while 

 many of these Compounds possess great toxicity in as low a conc. as 

 50 parts per million (0.005 per cent), a saturated sol. of di-hydroxy 

 stearic acid [which has just this conc. and which Schreiner and 

 Skinner (1910) have shown to be decidedly injurious to wheat seed- 



with tyrosin sol. The blackening of the jell of the Rana sylvatica eggs can be 

 easily explained by the presence of large amounts of tyrosinase [Banta-Gortner, 

 1913 (b)]. 



