EXPERIMENTAL MORPHOLOGY 



CHAPTER I 



ACTION OF CHEMICAL AGENTS UPON PROTOPLASM 



IN this chapter it is proposed to consider (I) the effect of 

 the various chemical agents upon the chemical constitution of 

 protoplasm, as revealed by the results of their application, 

 death, modification of the metabolic processes, and of rate of 

 movement ; (II) the phenomena of acclimatization to chemi- 

 cal agents ; and (III) the effect of such agents in determining 

 the direction of locomotion, chemotaxis. 



1. MODIFICATION OF VITAL ACTIONS* 



The vital processes are chemical processes, taking place in a 

 highly complex, very unstable, constantly changing substance, 

 whose activities we call life. It is not easy to study this 

 living substance chemically by the ordinary methods ; for 

 these usually, first of all, kill the substance. That the living 

 substance and the dead are quite different is illustrated, for 

 example, in the action of diamid (N 2 H 2 ) and hydroxylamine 

 (XH 2 O H), which show no action upon dead protoplasm, 

 but are powerful poisons for all living plasm. The instability 

 of protoplasm enables us, on the other hand, to make use of 



* In the preparation of this section, much use has been made of the admirable 

 work of LOEW ('93). Not only is the adopted classification of poisons for the 

 most part his, but also, in a few cases, passages from his book have been translated 

 in toto here. Most of the determinations of killing strengths of the various re- 

 agents for which no other authority is given have been taken from LoEw'sbook. 



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