298 BOTANICAL GAZETTE [NOVEMBER 
non-electrolyte. MV at o°C., is 1686 of mercury, or 22.18 
atmospheres. 
TABLE I. 
Partial pressures in terms of V 
Salt ae $ Ps P . 
Ca(NO,), - - .07143 3 .21429 .28571 .175004 [2.45 
KNO,- - - 02857 2 05714 08571 055712 [1-9 
MgSO, - - - .02381 2 .04762 04762 035712. [Ee 
MghtPO, + - .01664 4 06655 .06736 | “ing uaue ee 
Total pressure - - - - - 38559 . 48641 
Drea 
This 2 per cent. strength is the most concentrated solution | 
have used. Anything stronger kills the alga almost immedi- 
ately. As we decrease the concentration below this standard 
2 per cent. strength the dissociation becomes more and nee 
complete. Thus as the concentration approaches zero as a limit 
the value of i approaches that of z. The value of ¢ for the dif- 
ferent concentrations used, as far as they can be calculated from 
the physical data at hand, are given in table II. Values for : 
H,HPO, are inserted for comparison, in place of those for y 
K,HPO,. Table II also shows the total pressures of the sac : 
ous percentages in terms of V. The pressures in column gor - 
be used throughout this paper, but instead of 0.3856 N 1 a 
write 3856 VX 10+, etc. ce 
TABLE IL. ed 
T. faces § a 
- OSE N. et DY Der cent,’’ Values of 7 calculated from conductivity shee 
eee ee Pee a HPO. % 
a! é Ca(NO,),| KNO, MgSO, | KsHPOs | a 
2. ; 
38559 | .486405| 2 2.45 1.9 1.50 "heme 
-289193 | .364804 | 1.5 2.5 (?) as 1.56 3.02 
192795 | .243203 I 2.55 ks ae ce 
-096398 | .121601 a 2.66 £98 os eo 
-048199 | .060801 ae a vei 1.68 ae oe 
totes .024320 S 2.9 BA re Pie 
+00064 -013160 .0 2 09 
7 The meaning of a and 4 is the same as in table I. 
