MECHANICAL EQ UIVALENT OF CONSCIO USNESS. 123 



scientific men possessed the most definite and conclusive 

 information respecting them, while it is unfortunately a fact 

 that not one of our self-confident scientific teachers can give 

 anything approaching an accurate and satisfactory account of 

 what takes place during the growth even of a hair or a nail of 

 man's body, or a bit of bone or any other tissue ; nay, they 

 do not know what goes on during the formation and growth 

 of one of the minute elementary parts of which any one of 

 the simplest tissues of man's body is constituted. 



Many of my readers doubtless suppose that the action 

 of the nervous system is at this time thoroughly understood, 

 and they will be surprised to be assured that no sufficient 

 and satisfactory explanation can yet be given of the pheno- 

 mena which succeed one another in the simplest and most 

 elementary nervous apparatus in nature ; nay, the mere 

 structural arrangement of the simplest nerve mechanism, 

 has not yet been conclusively determined. 



Those who are indisposed to go so far as to accept the 

 doctrine that consciousness like heat has its mechanical 

 equivalent, and are not quite convinced that the conscience 

 is a property of matter, and man's moral faculties, as well 

 as his moral sense, mere functions of matter, as much pro- 

 ducts of evolution as the nerves and muscles that take part 

 in expression or in locomotion, are sometimes spoken of 

 with the utmost contempt, and delegated to a class of pre- 

 judiced ignoramuses, said to be fast becoming extinct, 

 though formerly respected and looked up to, having the 

 grand title of metaphysicians. Those who do not believe 

 in the physical nature of man are considered to be remark- 

 able for a certain weakness of intellect, are said to be 

 ignorant of physics, and not able to comprehend observa- 



