12 



CHEMICAL AGENTS AND PROTOPLASM 



[Ch. I 



TABLE III 



Time (in Hours) of Resistance Period of Spirogtra Communis to 

 Various Alcohols 



From these experiments it appears that allylic alcohol is more 

 injurious than the others, so that Tsukamoto ('95, p. 281) 

 believes it to attack the protoplasm directly rather than to act 

 merely catalytically. We see also that the rule enunciated 

 above about the greater activity of substances with more com- 

 plex alkyls holds true in general. Of the butylic alcohols the 

 normal is the most poisonous ; the tertiary, least. 



Carhonic disulphide (CSg) is one of the more powerful cata- 

 lytic poisons. A saturated aqueous solution, which contains 

 only a trace of CSg, nevertheless kills quickly algse, bacteria, 

 and the lower water animals. (LoEW, '93, p. 29.) 



6. Poisons which form Salts. — This is the third group recog- 

 nized by LoEW. In this case we have to do with acids and 

 bases which unite with the protein substances of the pro- 

 toplasm-producing salts. Thus disturbances leading to death 

 are produced. In addition this group comprises the poisonous 

 metallic salts. So we may recognize three groups : a. acids; 

 b. the soluble mineral bases ; c. salts of heavy metals. 



a. Acids. — The strong inoryanie acids act, in general, more 

 powerfully than the organic. Most bacteria, algae, and Infusoria 

 are very sensitive to inorganic acids (see MiGTJLA, '90), but 

 splenic fever bacteria resist 1% HCl for 24 hours, and their 

 spores 2% HCl for 48 hours. Mold withstands 1% phos- 

 phoric acid. Certain tissues have gained a high resistance 

 capacity to inorganic acids. Thus, the gland cells of marine 



