Nov. 19, 1917 
Reactions of Phosphorus of Root of Turnip 
363 
EXTRACTIONS OF THE FRESH PULP 
To determine in fresh turnips the proportion of the total phosphorus 
which is present in solution, the following method was used: Trimmed 
and cleaned fresh turnips were weighed and halved. Wedge-shaped 
portions with the edges at the center were grated off and the remainder 
of the turnips weighed, so that the amount of the grated portion could 
be determined by difference. 
The amount of water and phosphorus was determined in the ungrated 
portion and the following average procedure was also carried out: Two 
hundred gms. of pulp were taken, 80 c. c. of water added in transferring 
the pulp and juice from the grater to the receptacle in which all was 
allowed to remain for about 24 hours, with occasional stirring, 230 c. c. 
of extract were obtained by filtering under pressure. Fifteen samples 
taken from a given field at eight different times during a growing season 
yielded on an average, in the trimmed fresh turnips, 91.4 per cent of 
water and 0.107 per cent of phosphorus pentoxid, 80 per cent of the 
latter being present in the liquid portion. In the determination of 
the amount of phosphorus in solution it was assumed that the liquid 
remaining in connection with the pulp after filtering, contained the same 
percentage of phosphorus as the filtrate. It was found that when the 
extraction was made by 0.2 per cent hydrochloric acid less total phos¬ 
phorus was extracted than when water was used, and furthermore that 
some analytical difficulty was experienced in this connection, especially 
with subsequent determinations involving ammonia, owing to the 
presence of pectin-like substances. Previous extraction of the fresh 
pulp with alcohol did not prevent 0.2 per cent hydrochloric acid from 
extracting the pectin-like substances from the pulp. 
A 2 per cent acidity produced by acetic acid did not result in the same 
difficulties with the pectin substances; therefore the hydrochloric extrac¬ 
tion of the pulp was abandoned. The following percentages of phos¬ 
phorus pentoxid calculated to dry turnips show that when fresh turnips 
are grated without and with the acetic acid considerably less phosphorus 
is secured in the solution when the acetic acid is present. 
Sample. I II III IV V VI VII 
Without acetic acid. o. 54 o. 76 o. 38 o. 54 o. 33 o. 37 o. 13 
With acetic acid.22 .61 .31 .52 .26 .26 .06 
It seemed to be immaterial whether the 2 per cent acidity was attained 
by adding acetic acid at the time of grating or to the turnip juice sub¬ 
sequently, for in different samples 0.260, 0.063, an d 0.025 P er cent were 
obtained in the filtered juice when the acetic acid was present at the 
time of grating, and 0.259, 0.055, and 0.026, respectively, when added 
to the juice itself before filtering—that is, the addition of acetic acid 
to the juice produced a precipitate which contained about the same 
amount of phosphorus as was left with the pulp when acetic acid was 
in contact with the same at the time of grating. 
