126 
PROFESSOR P. F. FRANKLAND AND AIRS. G. C. FRANKLAND ON 
of the organisms taken from the ammoniacal and nitrifying solution inoculated from a 
broth-tube, which had itself been inoculated from a previous nitrifying solution ;— 
Fig. 3. 
Not only, however, is tlie growth in broth much more rapid when the inoculation is 
made from a previous broth-tube, instead of from the nitrifying solution itself, but on 
inoculating from the broth into gelatine-peptone, a very slow growth actually makes 
its appearance in the latter. 
This growth in the gelatine appeared after about three weeks in the first inoculation 
from broth, but on subsecjuently inoculating from this gelatine-culture in gelatine 
again, the growth was more rapid, appearing in from ten to twelve days. 
This gelatine-growth appears as a transparent, smooth, shining, thin greyish expan¬ 
sion on the surface, which slowly increases in thickness, and causes a depression with 
gradual lic[uefaction. On microscopic examination, the growth was found to consist of 
small bacilli, often hanging together in pairs, in fact their appearance was intermediate 
between that of the bacilli from broth on the one hand (fig. 2) and from the nitri¬ 
fying solutions (figs. 1 and 3) on the other. Fig. 4 represents the appearance of the 
organism taken from a gelatine cultivation. 
Fig. 4. 
Our nitrification ex};erlments wuth these broth and gelatine cultures have not yet 
proceeded far ; we have, however, already obtained undoubted conversion of ammonia 
into nitrous acid by means of two of the liroth-cultures. Thus a broth-tube was 
inoculated from one of the pure nitrifying solutions on October 21, 1889 ; on November 
2, 1889 (be., after tw'elve days), the broth had become slightly turbid ; on November 4, 
1889, two bottles containing ammoniacal solution were inoculated from the broth-tube; 
one of these bottles was placed in the incubator at 25° to 27° C., whilst the other was 
left at the ordinary temperature of the air. On December 17, 1889 (or after forty- 
three da}/s), the incubator-bottle gave undoul:)ted reactions with both diphenylamine 
and sulphanilic acid. On January 10, 1890, these reactions had become very strong, 
and on February 12, 1890, the mineral nitrogen was quantitatively determined 
according to the methods described on page 122, with the following results :— 
Ammoniacal nitrogen = 10’70 parts per 100,000. 
Nitrous ,, = 140 ,, „ 
Total . . . 11'80 
