650 Moral Epidemics and Contagions. [November, 
establish as preliminaries certain points which are based 
upon the most advanced data of different sciences. 
1. In our studies the grand problem of the transformation 
of motion has taken, we believe, a step in advance. We 
have proved that the transmission and transformation of 
motion may be effected in a number of cases, and in parti- 
cular in the cases in question, without the movement losing 
its co-ordination. On being transmitted to different media, 
cerebral or psychic, then purely physiological and physical, 
then again physiological and psychic or cerebral, it presents 
in the different media different phenomena, but on repassing 
into the same medium it reproduces the same phenomena — 
the movement appears co-ordinated in the same manner. 
We are, indeed, thus led to ask if the mythic Proteus does 
not symbolise knowledge formerly possessed, then lost, and 
finally re-discovered. 
2. On accurately summing up the most recent physiolo- 
gical discoveries we are necessarily led to consider the 
organisation, in its most general functions, as being merely 
a conductor and transformer of motion, and to find that we 
only reach the scnsorium commune, the ego, by motion, and 
that the ego only manifests itself or responds by motion, — a 
motion special and co-ordinated for each phenomenon. 
When the organs are diseased they affedt the nature and the 
conductivity of this movement in different manners. Hence 
the perturbation remarked in the psychic phenomena. 
3. We have brought the fadt prominently forward that to 
a given cerebral movement there always correspond identical 
and analogous phenomena. Thus the cerebral movement 
which produces laughter is not the same as that which gives 
rise to yawning, &c. 
4. The cerebral movement transmitting itself from brain 
to brain, through the ambient medium, without losing its 
nature, must consequently reproduce — or tend to reproduce 
— in any other brain which it reaches all the phenomena 
which depend upon it in the brain where it originated. 
5. The ordinary ambient physical medium which serves 
as intermediary for a cerebral movement in passing from 
one person to another are the sonorous and the luminous 
vibrations. [Also the olfadtory movements ?] We have 
studied the movements, and the relations of these various 
waves, and found that they concur perfectly in the repro- 
duction of the same phenomena, — that they may adt sepa- 
rately or simultaneously, in spite of the difference in their 
nature and the diversity of their rates of movement. They 
are added together when they adt simultaneously to reproduce 
