56 
CHEMISTRY: J. KENDALL 
Proc. N. A. S. 
ties arranged in order of intensity from white to intense dark red is one of 
graduated differences in amount of a single pigment rather than in quali- 
tatively different pigments. A definite alternative analysis can, however, 
be made even for these semi-quantitative characters by growing successive 
generations of segregating progenies until the progenies have been freed 
of segregation products other than those which it is desired to analyze. 
Furthermore, the establishment of constant derivative races and the subse- 
quent study of intercrosses among them has been found to result in simpli- 
fication of the difficulties of analysis. Both of these methods evidently 
depend upon stabilizing the residual genotype, which is a prime desideratum 
in the accurate analysis of semi-quantitative characters. The fact that 
such simplification of segregation can be accomplished and that semi- 
quantitative characters may then be subjected to analysis according to 
the qualitative mode of procedure argues not only for the adequacy 
of Mendelian principles in these cases, but for the identity in principle 
of qualitative and quantitative characters. 
The experimental data cited above were obtained from cultures made 
possible by a portion of the Adams' Fund allotted to the Department of 
Botany by the Department of Agriculture of the University of California. 
The detailed account of this series of studies will appear in a forthcoming 
number of Vol. 5 of the University of California Publications in Botany 
under the title, Studies of inheritance in Nicotiana Tabacum, I. A re- 
port on the results of crossing certain varieties. 
1 Comes, O. : "Monographic du genre Nicotiana comprenant le classement botanique 
des tabacs industriels," Atti. R. Inst. Incoraggiamento, Napoli (Ser. 5), 1, 1899. 
"Delia Razze dei Tabacchi Filogenesi, Qualita ed Uso," Ibid., 57, 1905. 
2 Anastasia, G. K. : Le varieta Tipiche della Nicotiana Tabacum L. Scafati, 1906. 
3 Setchell, W. A.: "Studies in Nicotiana, I," Univ. Calif. Publ. Botany, 5, 1912 (1-88). 
4 Allard, H. A., "Some studies in blossom color inheritance in tobacco, with special 
reference to N. sylvestris and N. Tabacum," Amer. Naturalist, 53, 1919 (79-84). 
THE CORRELATION OF COMPOUND FORMATION, IONIZATION 
AND SOLUBILITY IN SOLUTIONS. OUTLINE OF A 
MODIFIED IONIZATION THEORY 
By James Kendali, 
Chemistry Department, Columbia University* 
Communicated by M. T. Bogert. Read before the Academy, November 17, 1920 
Introduction. — The anomaly of strong electrolytes has been a notoriously 
weak point in the ionization hypothesis ever since its inception. In fact, 
satisfactory agreement with the Ostwald dilution law (which follows from 
the application of the law of mass action to the ionization equilibrium 
RX R + + X~) has been definitely established only for two restricted 
types of electrolytes (weak acids and bases) in a single solvent (water) 
through a limited concentration range (dilutions greater than iV/16). 
