PHYSIOLOGY, CHEMISTRY AND MORPHOLOGY. 383 



nerves, serves to overcome tlie cliemical affinities opposed to the syn- 

 thetic forniation of great molecular comx)lexes, and, setting np restora- 

 tive chemical processes, causes the diminution or cessation of functional 

 acts of a disintegrating chemical character. 



In addition to these phenomena of inhibition, which we may term 

 perii)heric, there are others of a central origin brought to light by the 

 investigations of Setchenow, Guyon, Golsy, and others. These have 

 shown that the nervous centers may exert a strong inhibitory action 

 upon reflex acts in general, and even, according to some experiments of 

 my own, upon the automatic activities of the medulla oblongata. This 

 restraining action of the nervous centers is closely connected with the 

 l)roblem of the physiological basis of thought.' In fact, the inhibitory 

 processes oppose such a resistance to the nervous vibrations passing 

 through the brain that impressions are necessarily arrested for a long 

 time within the sphere of the sensorium, and may thus induce that 

 associated series of conscious phenomena that lies above the sphere of 

 mere sensation or motion. Besides, the restorative chemical character 

 of the processes of inhibition explains to us the phenomena of memory, 

 without which we Avould be unable to understand consciousness. The 

 intensity of the psychical act is therefore in direct proportion to the 

 force of the restraining act. It would take too long to refer, even in 

 passing, to the importance of inhibition in all psychical operations. 

 We will merely allude to the fact that education, M'hich contributes to 

 form the character of the child, is valuable in proportion as it trains 

 the capacity for controlling the instinctive impulses of human nature. 



Thus it is that, starting from the arrest of the movements of the heart, 

 we may, by a gradual succession offsets and deductions, finally attack 

 one of the most difficult, and certainly one of the highest, problems of 

 physiology — that of the functional basis of thought. We can thus 

 prove that both the simplest acts of the vegetative life of a tissue, as 

 well as the most complex jpsychical nninifestations of a superior organ- 

 ism, have for their essential basis chemical i^rocesses of the same nature. 



But we must not boast too much over these results; for while, in the 

 concrete case we have cited, chemical antagonism helps to explain the 

 relation between inhibition and movement, chemistry can not usually 

 reveal the modus operandi of a functional act. 



From the chemical processes of our organism there are, as we have 

 already said in another form, effects derived of two kinds — either liber- 

 ation of energy in actions attended with the disengagement of heat or 

 its accumulation in processes during which such disengagement does 

 not take place. But if we were acquainted with the innumerable reac- 

 tions that take place in our organism, which for the greater j^art are 

 entirely unknown to us, we would yet have to find out how the energy 



'Fano (Giulio). Saggio speriinentale sul mecanismo del movementi volontari 

 nella Testuggine palustre. Reale Istituto di studi Superiore, Fireuze, 1884. 



