Ocroser 18, 1918] 
UNIVERSITY AND EDUCATIONAL 
NEWS f 
Firms in Manchester have offered to the 
College of Technology, Manchester, the sum of 
£3,000, spread over a period of five years, to- 
wards the cost of establishing a new depart- 
ment of industrial management. 
Accorpine to the Journal of the American 
Medical Association the conflict that has been 
going on in the University of Cordoba has 
grown more acute. The rector and several of 
the members of the faculties have presented 
their resignations. The head of the national 
government has appointed the minister of 
public instruction to take charge of the matter 
personally, and reorganize the staff of the uni- 
versity. At the request of the minister of 
public instruction, the medical faculty of the 
university of Buenos Aires did not appoint a 
new dean at the close of the term of office of 
Dr. Bazterrica, and this post is filled provision- 
ally by the member of the university council 
who has been longest in office, Dr. E. Canton, 
until the reorganization of the university 
statutes has been sanctioned. 
Dr. WitHrow Morse has been appointed 
professor of physiological chemistry in the 
medical school of the University of West Vir- 
ginia, Morgantown. 
Dr. Evcene L. Porter, instructor in phys- 
iology at the Medical School of the University 
of Pennsylvania, has accepted the position of 
assistant professor of physiology at the West- 
ern Reserve University Medical school. 
Owrne to the death of Professor R. E. 
Sheldon and the resignation of several mem- 
bers of the staff, the department of anatomy, 
University of Pittsburgh has been reorganized. 
The present members of the instructing staff 
are Professor Robert Retzer, associate pro- 
fessor C. C. Macklin and Assistant Professor 
Harley N. Gould. 
DISCUSSION AND CORRESPONDENCE 
CORRELATION OF THE HYDROGEN-ION EX- 
PONENT AND OCCURRENCE OF BACTERIA 
IN SOIL 
In an interesting note in Science (Vol. 48, 
pp. 139-140), followed by a fuller account in 
SCIENCE 
393 
the Journal of Agricultural Research (Vol. 14, 
No. 7, pp. 265-271, 1918), Mr. P. L. Gainey 
has recently described experiments showing 
that the occurrence of Azotobacter in soils is 
controlled, apparently to a major extent, by 
the hydrogen-ion concentration, the limiting 
hydrogen-ion exponent being about 6.0. Pre- 
viously to this, Christensen in Denmark had 
described some experiments on this general 
subject, besides those reviewed by Gainey. 
Christensen mentions having applied the 
Azotobacter test and the litmus paper test to- 
gether to about 40,000 soil specimens. He 
found a general correlation between acidity to 
litmus and absence of Azotobacter. He also 
found a close correlation between the Azoto- 
bacter test and a para-nitrophenol test: “ In- 
the case of soils showing a neutral reaction 
for litmus, there is a distinct difference be- 
tween the two groups,—with and without 
Azotobacter vegetation—for the former colors 
the liquid (para-nitrophenol) somewhat more 
yellow than the latter.” In applying para- 
nitrophenol, a solution of it was mixed with 
the soil, and the soil particles allowed to 
settle out over night. 
There is considerable objection against mix- 
ing the indicator with the soil mass, and espe- 
cially in the case of a one-colored indicator 
like para-nitrophenol, for any loss of indicator 
due to absorption by the soil mass would not 
be distinguishable from an actual color dis- 
charge due to acidity. The procedure of 
Christensen has been checked only by means 
of the litmus paper and the Azotobacter test 
itself. If the absorption of indicator is not 
serious, the results of Christensen can be in- 
terpreted in terms of hydrogen-ion exponent 
and are then in accord with the results of 
Gainey, for the turning point of para-nitro- 
phenol is about 6. 
The procedure used by Gainey, on the other 
hand, is the one used by the writer in 1916, 
tested by means of electrometric measure- 
ments of the soil suspension, and found to 
give at least approximately correct results.” 
1 Soil Science, Vol. 4, pp. 115-178, 1917. 
2 Jour. Wash. Acad, Sci., Vol. 6, pp. 7-16, 1916. 
