416 FRAGMENTS OF SCIENCE. 



" Who dares to name His name, 

 Or belief in Him proclaim, 

 Veiled in mystery as He is, the All-enfoldcr ? 

 Gleams across the mind His light, 

 Feels the lifted soul His might, 

 Dare it then deny His reign, the All-upholder ? " 



One or two interpolations excepted, the foregoing brief 

 article was written on an Alpine slope in the summer of 

 1863. Seven years afterward I was singularly interested 

 to learn, that nearly 300 years ago, in explaining the actions 

 and energies of the human body, Descartes employed 

 similar imagery and expressed similar views as far as the 

 knowledge of his time allowed. Professor Huxley, who 

 possesses a reading faculty which I can but envy, has pub- 

 lished in his " Lay Sermons " the following remarkable 

 extracts from the " Traite de l'Homme : " 



" Jn proportion as these spirits" (the animal spirits) " enter the cavi- 

 ties of the brain, they pass thence into the pores of its substance, and from 

 these pores into the nerves ; where, according as they enter, or even 

 only tend to enter, more or less, into one than into another, they have 

 the power of altering the figure of the muscles into which the nerves are 

 inserted, and by this means of causing all the limbs to move. Thus, as 

 you may have seen in the grottoes and the fountains in royal gardens, 

 the force with which the water issues from its reservoir is sufficient to 

 move various machines, and even to make them play instruments, or 

 pronounce words, according to the different disposition of the pipes which 

 lead the water. 



" And, in truth, the nerves of the machine which I am describing may 

 very well be compared to the pipes of these water-works ; its muscles 

 and its tendons to the other various engines and springs which seem to 

 move them ; its animal spirits to the water which impels them, of which 

 the heart is the fountain; while the cavities of the brain are the central 

 office. Moreover, respiration and other such actions as are natural and 

 usual in the body, and which depend on the course of the spirits, are 

 like the movements of a clock, or of a mill, which may ?jc kept up by the 

 ordinary flow of water. 



