46 REPORT OF THE BACTERIOLOGIST OF THE 
INTRODUCTION. 
The idea of using bacterial cultures for inoculating legumes 
in order to fix nitrogen from the air is an old one. It was quite 
prominently before the public about 10 years ago’ but became dis- 
credited because the cultures were not found to be effective. 
During the past two years this idea has again been brought to 
public notice’ through the announcement that the Department 
of Agriculture at Washington had solved the problem of pre- 
paring active cultures in convenient form for distribution. The 
new method (see Letters Patent, page 51) consists in growing 
Pseudomonas radicicola (Byerinck) Moore, the germ necessary to 
the fixation of nitrogen, in a solution poor in nitrogen, and then 
transferring this growth to absorbent cotton. When dried this 
cotton can be sent through the mail. On receipt by the farmer, 
the cotton is dropped into a solution prepared from chemicals 
and clean water. After developing for two or three days this 
solution is applied to the seed. For the season of 1904, the 
Department sent out large numbers of cultures. Some of the 
results from their use are given in a bulletin? which was issued 
Jan. 23, 1905, and distributed early in February. 
Interest in the subject grew so rapidly that by February 27 
all the cotton cultures which the Department would be able to 
supply to farmers before July 1* had been promised. This made 
it necessary for a large number of interested farmers either to 
omit the use of cultures or to purchase the material in the open 
market. 
During the past winter and spring, inquiries were constantly 
coming to the Station from farmers regarding commercial cul- 
tures for inoculating legumes. Many of these inquirers asked 
specifically concerning the purity and quality of the commercial 
cotton cultures. As this was the first season these firms had 
been doing business, we lacked data from which to answer these 
questions. This bulletin gives the results of an attempt to secure 
such data. 
*Goessman, C. A. Experiments with “ Nitragin.” Hatch Exp. Station, 
Report, 9:177-189. 1897. 
“Grosvenor, G. H. Inoculating the soil. A remarkable discovery in scien- 
tific agriculture. Century Magazine, page 831. October, 1904. 
3Moore, G. T. Soil Inoculation for Legumes. Bul. 71, Bureau of Plant 
Industry, U. 8. Dept. Agr. 
“See circular, page 50. 
