358 BOTANICAL GAZETTE ~ [NOVEMBER 
KAHLENBERG AND AUSTIN have been continuing the earlier researches 
on the toxic action of various substances on seedlings. They conclude! 
that the toxicity of acid sodium salts is greater than it ought to be if it were 
due solely to H ions and that the theory of electrolytic dissociation is unsatis- 
factory in explaining the poisonous action of these acid salts and of acids 
as well. The true explanation, they suggest, is very likely to a: found in 
the ability which the substances all have in common, to neutralize basic sub- 
stances. This explanation is independent of the theory of electrolytic dis- 
sociation. Kahlenberg also found himself unable to explain the sour taste of 
acids on the basis of the H ions? and holds the physiological effect tobe due 
to their chemical activity in virtue of the fact that the H is replaceable bya — 
metal of a basic radical. The more readily the H is replaced, the more — 
reactive the acids are and the more intense is their taste.—C. R. B. 
Dr. Gino PoLvaccr published a year ago the results of some of his 
researches on photosynthesis ® which have not been adequately noticed in this 
journal. His most important results are as follows: : 
Green organs of plants which grow in sunlight give the aldehyde reaction : 
with Schiff’s reagent. Under the same conditions fungi do not so react; nor 
do leaves, kept for some hours in darkness or in an atmosphere free of CO3. 
Formic aldehyde reactions are also obtained from expressed sap by proper 
treatment. He holds, therefore, that formic aldehyde is produced by gre? 
organs under the normal conditions of photosynthesis, and promises — 
the results of his researches on the process of its formation in a sec 
memoir—C, R. B. 
THE CORRECTION of a large number of typographical and other errors, 
both of omission and commission, in Engler and Prantl’s Pflanzery 
especially in the general index, will be found in Ad/gemeine Bot. — 
1900: 110 e¢ seg. Otto Kuntze and Tom von Post are the ferrets. — e J 
inclined to magnify and multiply the errors, which they figure at 93 
they have done a service for bibliographic work which will mc RB 
users of the Pflanzenfamilien some hours and much bad temper. —C. 
*Jour. Phys. Chem. 4:553-569. 1900. Jour. Phys. Chem. 4::533-537" me 
*° Atti Instituto Botanico de Pavia N. S. 73(1-21). 1899. 
