Igor] OPEN LETTERS 439 
Kahlenberg and True) concerning these acids are both clearly headed ‘gm. 
equiv. per liter,” which excludes all possibility of misconception. Mr. Dan- 
deno clearly isin error; and for the piquant remarks in which he indulges on 
p. 234 of his article in referring to the comments of Kahlenberg and True on 
the behavior of maleic and fumaric acids, he deserves sharp censure. 
Mr. Dandeno further complains that Heald * states in referring to Kahlen- 
berg and True, “ in these experiments the solutions were prepared according 
to gram-equivalents,” and then Dandeno adds that on pp. t19—123 of Kahlen- 
berg and True we find written “ gram-mol. per liter.’ Now it happens that 
all the acids listed on pp. 119-123 by Kahlenberg and True are mono-basic 
acids, and that in the case of these a gram-molecule per liter is identical with 
a gram-equivalent per liter, so that Heald was correct in his statement. vie 
dently Mr. Dandeno failed to note the basicity of the acids listed by Kahlen- 
berg and True on the pages last mentioned. 
The two instances that Dandeno mentions, in which Kahlenberg and 
True have stated that a gram-equivalent is contained in so many liters of 
water instead of so many liters of solution, are cases in which the solutions in 
question were so extremely dilute, that no difference could be detected were 
the solutions made up on the one basis or the other. The instances occur, 
Moreover, in the course of a preliminary general discussion where no sharp 
comparison is involved. 
I have not taken the time to look up the work of the various other inves- 
tigators that Mr. Dandeno attempts to criticise. It is of course possible that 
mistakes have been made; but from what has been said above, the reader 
Can readily form an opinion as to Mr. Dandeno’s competency to make such 
Criticisms. 
In conclusion, I wish to emphasize once more that all the solutions used 
by Kahlenberg and True were of exactly the strengths indicated in their 
tables, that the conclusions based upon them are correct, and that the inter- 
pretations of Mr. Dandeno are entirely wrong.— LouIs KAHLENBERG, Lad- 
oratory of Physical Chemistry, University of Wisconsin. 
I am limited to a brief reply to the foregoing letter. Regarding it I have - 
to say: : 
It is fully explained in my paper 5 that, in the case of monobasic acids and 
salts with monad metals, gram-molecule and gram-equivalent solutions are 
the same. It was only where basicity differed that exception was taken. 
In view of Dr. Kahlenberg’s assertion, 1 withdraw fully the statement 
that the solution of sulfuric acid referred to was purchased from the chemist. 
I had Dr. True’s statement that it was, but ] must have misunderstood him. 
However, Dr. True states,® referring to this table (H,SO,) headed 
* Bor. Gaz. 22: 125. Aug. 1896. 5 Bot. GAZ. 32: 230-232. Oct. 1901. 
° Quoted /. ¢., p. 233. 
