550 THE DISEASES AND DISOEDERS OF THE OX. 



new lines, that we are endowed with powers of dealing with 

 disease and of prolonging life which, if they could have conceived 

 of them by way of guesswork, our ancestors, judging from their 

 point of view, would perhaps have only slightly modified their 

 ideas as to the possibility of finding out an " elixir of life " by 

 which men could be made immortal upon the earth, and the philo- 

 sopher's stone whereby all baser metals might be convertible into 

 gold. Every now and then one is apt to forget the possibilities 

 of this time and age, every now and then we require a mental 

 stimulant to refresh us in our searchings after the truth. Every- 

 day laborious work is all the better for a little of the spirit or 

 aspiration, and it is a joyful thing for those who can infuse it 

 into their toil to cultivate the power as well as the will to do so. 

 In his second Dissertation to Kiolan, Harvey, as mentioned 

 by Lewes, says : — 



Some weak and inexperienced persons vainlj' seek by dialectics and far-fetched 

 arguments either to upset or establish things that are only to be founded on 

 anatomical demonstration and believed on the evidence of the senses. He who 

 truly desires to be informed of the question in hand must be held bound either 

 to look for himself, or to take on trust the conclusions to which they who have 

 looked have come. 



Unfortunately, in the present state of science, the ideas which 

 physiologists have as yet arrived at regarding the working of the 

 nervous system are very unsatisfactory and incomplete. We 

 have no space to say more here on this subject than that it 

 is probable that some great discoverer, some earnest, patient, 

 plodding, life-worker, as great or even greater than Harvey, is 

 now needed to apply all the delicate methods of modern science 

 to the elucidation of the wonderful part which the nervous 

 system plays in all higher forms of life. At present it is 

 quite impossible to clear up the methods by which the chemical 

 and physical actions going on in nerve-cells and nerve 

 fibres produce the complex and most peculiarly involved 

 phenomena presented by all living beings which have reached 

 any marked degree of development, and especially by human 

 beings. 



It may perhaps seem strange, but it is true, that physiologists 

 know very little concerning the inner working of the brain and 

 nervous system generally. Indeed, great advances must be 



