§ 1] MODIFICATION OF VITAL ACTIONS 7 



by alkaline (0.001%) silver solutions. Other basic substances, 

 like potash and organic amine bases, and various alkaloids, 

 produce the same effect. (Cf. Loew and Bokorny, '89.) 

 Azoimid. — LOBW ('91) has studied the effect upon proto- 



plasm of this somewhat close ally of ammonia, || /NH. The 



poisonous action of this substance seems to depend upon its 

 excessively unstable structure, for it easily disintegrates with 

 violent explosion and production of ammonia. This latter 

 then produces the characteristic granulations. Infusoria are 

 killed in 2 to 2|- hours by a 0.1% solution of NgNa, and the 

 water-living Nematodes, Planaria, Ostracoda, Copepoda, and 

 young Planorbis and Lymneea are killed by a 0.05% solution in 

 30 to 40 minutes. Algae are more resistant. 



5. Catalytic Poisons. — There is a large number of unstable 

 C-compounds which are neither acid nor basic nor characterized 

 by chemical energy, which are, nevertheless, intense poisons 

 for all living cells. Here belong the anaesthetics — ethylether, 

 chloroform, chloral, carbontetrachlorid, methylal, alcohols, car- 

 bon disulphide, etc.* 



Nageli believes these to act as poisons by virtue of an in- 

 herent lively condition of molecular movement, which disturbs 

 the normal condition of movement in the living plasma body, 

 and, on that account, produces death. LoEW believes, more 

 precisely, that the transmitted condition of violent movement 

 leads to chemical transformations in the unstable albumen of 

 the protoplasm. 



As examples of the effect of the mere presence of many un- 

 stable carbohydrates upon chemical processes, it has been found 

 that HCl and prussic acid, which unite alone only at a high 

 temperature, unite in the presence of various ethers at —15°. 

 Again, the mere presence of some CH compounds transforms a 

 substance into its isomeric condition. Thus, thiourea is trans- 

 formed by an alcoholic solution of amylnitrite into its isomer 

 rhodanammonium. Such poisons, which change the protoplasm 

 by transmission of molecular movements, may be called cata- 



* This paragraph and the two following are largely translated from Loew 

 ('93). 



