368 NUTRITION. 



mensurate with that of the question of the soul, and its rela- 

 tions to the finite and the infinite ; a question which philoso- 

 phers have been constrained either to admit upon the faith 

 of revelation, or to hopelessly abandon. Little, if any, real 

 progress is to be made by endeavoring to cover the inscruta- 

 ble problem of life with a simplicity entirely artificial. This 

 will always be attractive, and, to a certain extent, satisfac- 

 tory to the minds of those unacquainted with the details of 

 natural laws, or willing to admit speculative theories upon 

 subjects concerning which it is impossible, in the present 

 condition of science, to have any positive information ; and, 

 if generally admitted by biological students, would carry 

 our science back to the dark periods in its history, when the 

 study of Nature was confined to speculation, and there ex- 

 isted no knowledge based upon the direct observation of 

 phenomena. A new name, arbitrarily applied to organic 

 matter, without any addition to its physiological history, 

 does not advance our definite knowledge. For example, it 

 has long been known that certain nitrogenized constituents 

 of the organism, classed collectively as organic principles, 

 seem to give to the tissues their property of self-regeneration 

 and development. It may seem to those not engaged in 

 scientific inquiry that a recital of the wonderful properties 

 of " protoplasm " affords some additional information con- 

 cerning the phenomena observed in organized bodies ; but 

 the true definition of the term leads us back to our former 

 ideas of the so-called vital properties of organic matters. 1 



It is a well-established fact that while nearly all of the 

 tissues undergo disassimilation, or conversion into effete 

 matter, during their physiological decay in the living organ- 

 ism, others, like the epidermis and its appendages, are 



1 HUXLEY, The Physical Basis of Life, New Haven, 1869, from the Fort- 

 nightly Review, for February, 1869. This very interesting and able discourse, 

 delivered originally before a popular audience, is referred to, not as a subject 

 for rigid scientific criticism, but as formularizing some of the prevalent ideas 

 concerning the properties of the so-called protoplasm. 



