ELISHA MITCHELL SCIENTIFIC SOCIETY 29 
His idea is that valence is dependent upon the form of the 
atom... He says; ‘‘The simplest observation teaches that 
every change from the spherical form must lead to greater 
changes in the attraction in certain directions, since the atom 
at these points can, so to say, be more closely approached. 
Each form of that kind therefore determines a certain num- 
ber of capacities for attraction or valences.” 
Ostwald’ comments upon this hypothesis as follows: 
“Tf we think of valence as a question of a property of the 
atom, whose action can be modified by the difference in the 
condition of the atom, especially in its motion, then it is 
thinkable that although the cause of the valence is un- 
changeable, the workings of this cause, that is the valence 
itself seems to differ from case to case. 
An hypothesis of this kind has in fact been suggested by 
van’t Hoff. In that he assumed that the chemical attraction 
between the atoms was'a consequence of gravitation, he 
showed that if an atom possessed a form differing from the 
spherical the intensity of the attraction on its surface must 
possess a definite number of Maxima. ‘The Maxima can be 
of varying value. If the motion of the atom from heat is en- 
ergetic only the greatest Maxima will be able to hold their 
atoms and the valence shows itself to be smaller by higher 
temperatnres than by lower which-corresponds with observa- 
tion. 
Lossen’s’ idea as to valence, deduced from the considera- 
tion of the theories of van’t Hoff and Wislicenus as to the 
space relations of the atom, seem to be condensed into the 
simple sentence: 
‘“This conception leads, in my opinion, necessarily to the 
assumption that the polyvalent atom cannot be regarded asa 
material point but that rather parts of it are to be distin- 
guished from which the influence goes out to other atoms.” 
Wislicenus® expressed his ideas as to valence as follows: 
‘‘T consider it not impossible that the carbon atom more or 
1 Lehrbuch der allg. Chemie I ed. I, 830. 
2Ber. d. Chem. Ges. 20, 3309. 
3 Ber. d. Chem. Ges. 21, 581. 
