410 Scientific Intelligence. 
long since observed by the English botanist, Robert Brown. The ex- 
planation depends upon the author’s views of the constitution of matter 
and of the relations between material and etherial particles. These views 
are in themselves worthy of attention as presenting some new points an and 
perhaps overcoming difficulties long since recognized. The author’s 
propositions are briefly as follows : 
Matter coysists of material atoms which mutually attract, and of 
etherial atoms which mutually papel each other. Material and ethereal 
atoms repel each other. 
2.) The heat of a body consists in a condition of vibration of its ethe- 
real atoms and material molecules. 
(3.) With an increase in extent of vibration is connected ; 
a. an increase of living force in the position of equilibrium. 
4 a diminution of the time of vibration 
an expansion of the body. For if after oh position of bebe 
hae existed, vibrations are excited stip this, the mean distance of two 
vibrating atoms is still the same as in the Shelton of equilibrius, but 
the mean of the varying forces is acai than the force in the position 
of equilibrium, because the forces diminish in some inverse ratio of the 
distances. The mean ths irartore’ increases with the extent of vibration, 
and expansion must e 
e temperatirres of two bodies are equal when the times of vibra- 
tion of the atoms in them are equa 
(5.) The quantity of heat conveyed to a body is the increase of the living 
force of the vibrating atoms and the work done by the change in the 
position of the atoms. The living force is here defined as ‘and 
not as mv? 
is work must be es gpa ey eee in overcoming internal forces wi 
the pers waned states may consist in two different directions of the 
vibrations of the ponderable molecules as compared with the directions 
of the vibrations of the ethereal particles. Thus in the one case the 
two sets of particles may vibrate in the same, and in the other case in 
opposite mera es: oie bodies the direction of the vibration of or 
moecles may noe Toe that sae sites 
