214 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1909. 
force. Experimental proof of the existence in a body submitted to a 
field normal to a luminous ray, of a longitudinal component of elec- 
tric force. 
As M. d’Arsonval has so aptly pointed out in his paper at the close 
of the conference, the study of these phenomena gives new results on 
the nature, the movements, and the number of the electrons which 
produce absorption. It contributes to the extension of our knowl- 
edge as to the ultimate constitution of matter. 
The study of the phenomenon of magnetic saturation at low tem- 
peratures permits, as M. Pierre Weiss has remarked, of the determi- 
nation of the magnetic moment of the molecule. This quantity is 
fundamental in the expression of the law of corresponding magnetic 
states, a law analogous to that of the same name which governs the 
compression and dilation of bodies. 
A study of such importance as the molecular modification of bodies 
is rendered possible by the well-known fact that electric conducti- 
bility increases as the temperature is lowered. The creation of pow- 
erful magnetic fields by simple coils cooled down and traversed by 
very intense currents, permits the realization of the atom, and allows 
it to be transformed and its movements modified. 
For this reason the first section of the congress adopted the fol- 
lowing resolutions presented by Messrs. Jean Perrin, Mathias, and 
Kammerlingh Onnes: 
(a) In view of the extreme importance which is attached to the 
modification of atoms and the possibility of attaining this result by 
means of an intense magnetic field (a possibility which the Zeeman 
phenomenon has already demonstrated), the congress offers the reso- 
lution that the nations should unite for the construction of a great 
electro magnet without iron, the efficiency of which shall be increased 
by an intense refrigeration. 
“(6) In view of the admirable scientific equipment of the cryogenic 
laboratory at Leyden and the hospitable offer of welcome made by 
Prof. K. Onnes to the investigators of all nations, the physicists pres- 
ent at the first section of the Congress of Refrigeration, express the 
following resolution: That the governments of the nations repre- 
sented at the congress should furnish necessary assistance to permit 
physicists to carry out at the cryogenic laboratory at Leyden re- 
searches with regard to physical properties at very low temperatures. 
“(c) The congress resolves that an international association shall 
be founded to further such study, scientific or otherwise, an associa- 
tion with its headquarters at Paris, which while aiding the already 
specialized fields of research shall undertake the study of the whole 
domain of low temperature. 
*P, Weiss: L’hypothése du champ moléculaire et la propriété ferro-mag- 
nétique. Revue générale des Sciences, February 15, 1908. 
