CHEMICAL PROPERTIES OF HAY INFUSIONS WITH 
SPECIAL REFERENCE TO THE TITRATABLE 
ACIDITY AND ITS RELATION TO THE PROTO- 
ZOAN SEQUENCE 
MORRIS S. FINE 
From the Sheffield Biological Laboratory, Yale University 
FIVE FIGURES 
In the preceding paper! are presented the results of a study of 
the succession of the protozoan fauna of a series of hay infusions. 
The present paper gives the results of some chemical investiga- 
tions on the infusions employed by Professor Woodruff with a view 
to correlating, if possible, certain chemical conditions with the 
protozoan sequence there shown to occur. 
Although one cannot hope to obtain a complete analysis of the 
chemical factors involved, there are a limited number of deter- 
minations which can be made with some degree of ease and accu- 
racy, and which may quite reasonably be expected to throw light 
upon this problem. In the present work a preliminary survey 
was made to determine those estimations which would be likely 
to yield satisfactory results, with the view of instituting an inten- 
sive study of such factors. The determinations? thus first made 
were: (1) Phenolphthalein acidity, (2) Methyl-orange alkalinity, 
(3) Oxygen consumed, (4) Chlorides, and (5) Solids (total, organic 
and inorganic). 
The ‘phenolphthalein acidity’ was obtained by titrating 5 ce. 
of infusion with 0.01 N NaOH, using phenolphthalein as indicator. 
17, L. Woodruff: Jour. Exp. Zool., vol. 12, No. 2. The present work was under- 
taken at the suggestion of Professor Woodruff, to whom I am indebted for 
suggestions and criticism. 
2 Cf. A. W. Peters: Amer. Journ. Physiol., vol. 17, p. 454, 1907. 
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