1898] RUDIMENTARY NERVOUS SYSTEM 335 
formed by Savart at the College de France seen the shape of some 
liquid veins change abruptly under the influence of musical notes 
entirely inappreciable to the ear, that were played at the Luxembourg. 
2. The figures below are most interesting : 
Velocity of light ; 300,000,000 metres a second. 
” electricity 180,000,000 
x sound : 331 ‘ 
ie liquid waves ! 10 * 
s nervous vibrations(Lobster) 8 is (Frédéricq) 
“1 ne faut pas confondre la pulsation, larrivée d’une onde, avec 
le mouvement de la circulation luicméme; on ne peut trop le 
répéter : unda non est materia progrediens, sed forma materiae 
progredientis: aussi Czermak a prouvé, par des recherches trés exactes 
(sphygmographe a miroir), que tandis que le mouvement du sang 
diminue de vitesse & mesure qu’on se rapproche des capillaires, la 
vitesse de propagation de l’onde pulsative va au contraire en aug- 
mentant du centre a la périphérie. Onimus a insisté sur ces 
caractéres de Vonde pulsative.” (Etudes sur les tracés obtenus 
par le sphygmographe. Journal d’anatomie, 1866.) ” 
It is then extremely probable that a nervous vibration is nothing 
more than a molecular one, the velocity of which varies in accord- 
ance with its conditions, though it never amounts to more than 
thirty or ninety metres per second. Here are some other proofs: 
3. I modified Secchi’s classical experiment? of pouring a few 
drops of alcohol on a thin bed of water, by substituting for the 
former a mixture of alcohol and castor oil, and adding to the water 
a considerable quantity of linseed oil. Under these conditions a 
strong agitation takes place. In like manner Longet provoked some 
local convulsions by touching the motor nerves with alcohol. 
4. In most cases mechanical excitation affords real and genuine 
success, and the excitability of the Helix nerves can only be 
evideuced by means of mechanical and physical irritants. (Milne- 
Edwards.) 
In some animals diverse concretions are present, which oscillate 
at the least agitation of the external fluid, and increase the mechanic 
vibration endured by the auditive nervous terminations, rather than 
translate any currents endowed with a mysterious nature.® 
I have made a small apparatus tending to demonstrate the in- 
fluence exercised by otoliths on the vibrations of mercury, It con- 
?Marey. Mouvements des ondes liquides dans les tubes élastiques. Jowrnal de 
physique, 1875, Vol. ix., p. 257. 
* Kiiss et Duval. Cours de physiologie, Paris, 1879, p. 259. 
* L’unité des forces physiques, Paris, 1874, p. 73. 
4 Traité de physiologie, Paris, 1869, Vol. iii., p. 209. 
° Béclard. Traité de physiologie, p. 961. 
®Chatin. Les organes des sens, p. 301. 
