1922] WILLAMAN & SANDSTROM—SCLEROTINIA 293 
juices, but with care in the renewal of the platinum an accuracy of 
0.3 millivolt was obtained. 
TANNIN.—The Procter-Léwenthal method as detailed in the 
Official Methods (1) was used. 
OXALIc actp.—In the case of the juice, 40 cc. were treated with 
80 cc. of 95 per cent alcohol, filtered, washed, and made up to 200 cc. 
Aliquots of this were used for oxalic and for malic and tartaric 
acids. For oxalic the alcohol was evaporated, the material neutral- 
zed with ammonia, acidified with acetic acid, filtered if necessary, 
treated with calcium acetate in the hot, the calcium oxalate filtered 
off, and titrated with permanganate. The precipitate no doubt 
was impure, as it adsorbed some coloring matter, but a satisfactory 
end point was obtained, and the results are at least comparative. 
In the case of the residue, 10 gm. was digested with 75 cc. of 0.8 
per cent hydrochloric acid for one hour, to liberate any oxalate - 
existing in the residue in the form of the calcium salt. The extract 
was treated as in the case of the juice. 
NirritEs.—The qualitative test with a-naphthylamine and 
sulfanilic acid was used. 
PROTEIN AND NON-PROTEIN NITROGEN.—Trichloracetic acetic 
acid was used as the protein precipitant. BuisH’s (8) copper 
hydrate method was tried in comparison with the trichloracetic 
acid. Since the latter gave the same results and is simpler to use, 
it was adopted. Twenty cc. of juice plus 20 cc. of 25 per cent 
trichloracetic acid were allowed to stand overnight, and the nitro- 
gen in a filtrate determined. In the case of the residue a 
weighed sample was extracted with boiling water, and the filtered 
extract treated with the protein precipitant. It was realized that 
in the case of the residue two factors for precipitating proteins were 
used, heat and the trichloracetic acid. This fact might give 
incomparable results on the two sets of samples, but there was no 
other apparent way of getting the data on the residue. 
MALIC AND TARTARIC ACIDS.—The optical method (51) for 
obtaining these two acids in the same solution was used, since it 
was thought possible that both were present, although BicELow 
and Dunsar (5) found only malic. If only one of the two acids 
be present when this optical method is used, the rotation readings 
