THE BIOLOGY OF DAILY LIFE. 93 



Thus, under the protoplasm hypothesis, it becomes 

 quite plain why we have this medley of chemical and 

 biological methods. This wild phantasmagoria of 

 microscopic forms, truly " separated by artifice and 

 not by Nature," and " like the painted clay," according 

 to the colours they assume under aniline dyes, is 

 simply an exhalation arising out of that Serbonian bog 

 which science has left too long undrained on the con- 

 fines of her cultivated territories, where chemistry loses 

 the exactness of its rational formulae,* and biology 

 is sunk in utter confusion of that most important 

 boundary line, which separates between the living and 

 the dead. 



* Eational formulae " are intended to indicate the chemical 

 nature of the compound and to express the relations in which 

 it stands to other bodies." (Roscoe's and Schorlemmer's Treatise 

 on Chemistry. Vol. ILL, Part I., p. 112.) It is evident that 

 protoplasm, being indefinite in its composition, can have no 

 rational formula. Its empirical formula is variable aud in- 

 constant. 



