chemical Libºº
Q\,
3
1423 A Study of the
Acid soluble Phosphoric Acid
in Eggs
DISSERTATION
Submitted in Partial Fulfilment of the Requirements for the
Degree of Doctor of Philosophy in the Faculty of
Pure Science, Columbia University.
By
LOUIS PINE, B.S., A.M.
- - New York City
1923



A Study of the
Acid-Soluble Phosphoric Acid
- in Eggs
DISSERTATION
Submitted in Partial Fulfilment of the Requirements for the
Degree of Doctor of Philosophy in the Faculty of
Pure Science, Columbia University.
- By
A &\
LOUIS PINE, B.S., A.M.
New York City
1923
6.4.4.2-lº, 64.
3 - 2,2'- 172%
TO MY WIFE
\
ACKNOWLEDGEMENT
The author wishes to take this opportunity of expressing his
indebtedness to Dr. John H. Larkin, Director of the Strecker Me-
morial Laboratory, Welfare Island, New York; to Professor
William J. Gies of Columbia University; and to Dr. Harry W.
Redfield, Chief of the New York Station, Bureau of Chemistry,
United States Department of Agriculture, for their encourage-
ment, advice, and many acts of kindness.
L. P.
New York Station,
Bureau of Chemistry,
United States Department of Agriculture,
May, 1923.
TABLE OF CONTENTS
Dedication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Acknowledgment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Method for the Estimation of the Acid-Soluble Phosphoric
Acid in Liquid Whole Egg and Yolk. . . . . . . . . . . . . . . . . 8
A Study of the Chapin and Powick Method for the Extrac-
tion of Acid-Soluble Phosphoric Acid. . . . . . . . . . . . . . . . 9
Plan of Investigation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Acid-Soluble Phosphoric Acid and Water in Whole Egg. ... 12
Acid-Soluble Phosphoric Acid and Water in Yolk.......... 17
Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Summary and Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Biographical . . . . . . . . . . . . . . . . . . . . . . . * e º e º e is e e e º e s e º e º 'º e s a 26
Publication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... 26
A STUDY OF THE ACID-SOLUBLE PHOSPHORIC
ACID IN EGGS
By Louis PINE
(From the New York Laboratory, Bureau of Chemistry, United
States Department of Agriculture)
INTRODUCTION
Chapin and Powick (1), while working on a method for the
estimation of the inorganic phosphoric acid in tissues and food
products, found that the inorganic phosphoric acid in eggs was
greatly increased on decomposition. They were interested only in
the method and did not make an extensive study of the quantita-
tive changes in inorganic phosphoric acid in eggs, as a test for
decomposition.
The total phosphorus pentoxide in eggs is given by Sherman
(2) as 0.37 per cent, by Cook (3) as 0.67 per cent and by Chapin
and Powick (1) as 0.5 per cent. About 96 per cent (1) of the
total phosphorus is organically combined. Practically all of the
organic phosphorus is in the yolk. The organic compounds of
the yolk containing phosphorus are proteins, chiefly vitellin, 15.7
per cent (4); phospholipoids, chiefly lecithin, 11 per cent (5);
and glycerophosphoric acid, 1.2 per cent (6), of the yolk.
Upon decomposition, the vitellin yields inorganic phosphoric
acid (7) and the phospholipoids liberate glycerophosphoric and in-
organic phosphoric acids (8). Chapin and Powick (1) found from
16 to 18 mgs. of inorganic phosphorus pentoxide per 100 grams of
fresh eggs and from 41 to 129 mgs. per 100 grams of decomposed
eggs, depending upon the degree of deterioration. Cook (3)
found a decrease in lecithin in cold storage eggs.
Since the phospholipoids on decomposition liberate glycero-
phosphoric acid as well as inorganic phosphoric acid, the increase
in the inorganic phosphoric acid alone would not be a complete
measure of the decomposition. The increase in the total acid-
soluble phosphoric acid, containing both the inorganic and the
glycerophosphoric acids, would be a better index of the decom-
position of the organic phosphorus compounds of the yolk.
This work was undertaken to ascertain whether the increase
of acid-soluble phosphoric acid in whole egg and yolk could be
made a test for decomposition. The white of egg was not consid-
ered in this investigation because it contains little organically com-
bined phosphorus, and therefore the increase of acid-soluble phos-
phoric acid on decomposition would be neglible.
7
METHOD FOR THE ESTIMATION OF THE ACID-
SOLUBLE PHOSPHORIC ACID IN LIQUID
WHOLE EGG AND YOLK.
There are three important steps in the determination of the
acid-soluble phosphoric acid in eggs: the extraction, the destruc-
tion of organic matter, and the final estimation of phosphoric
acid. The extraction is made by a modification of the Chapin
and Powick method (1). The organic matter is destroyed by di-
gestion with concentrated sulphuric and nitric acids. The phos-
phoric acid is determined as magnesium pyrophosphate.
ExTRACTION.—Fifty grams of whole egg or 25 grams of yolk
are weighed out in a 500 c.c. Erlenmeyer flask. 200 c.c. of hydro-
chloric acid solution, containing 1 c.c. of concentrated hydro-
chloric acid (0.5:100), and 8 grams of picric acid are added. The
flask is stoppered with a rubber stopper and shaken vigorously at
frequent intervals, at least every ten minutes, for one hour. The
contents is then filtered through a folded filter paper, 24 cm. for
whole egg and 18.5cm. for yolk. The filtration should not be al-
lowed to proceed for more than three-quarters of an hour.
DESTRUCTION OF ORGANIC MATTER.—125 to 150 c. c. of the
filtrate are transferred to a 500 c. c. Kjeldahl flask. Four glass
beads, 10 c. c. of concentrated sulphuric acid and 10 c. c. of con-
centrated nitric acid are added. The mixture is boiled down until
white fumes appear. About 2 c. c. of concentrated nitric acid are
added drop by drop and the mixture is boiled again until white
fumes appear. This last step is repeated four times. The mixture
is boiled ten minutes longer and then allowed to cool. About 25
c. c. of water are added and the solution boiled until the brown
fumes are driven off.
ESTIMATION OF PHOSPHORIC ACID.—The solution, while still
hot, is transferred to a 400 c. c. beaker and the flask washed with
small amounts of hot water until the volume of solution in the
beaker measures about 100 c. c. The phosphoric acid is then de-
termined by the official gravimetric method (9).
The total volume of solution in the extraction mixture is found
by adding to the 200 c. c. of hydrochloric acid solution the volume
of water contained in 50 grams of whole egg or 25 grams of yolk
and in 8 grams of picric acid (1).
Water in eggs is determined in vacuum at 55° C. (10) and
in picric acid in vacuum over sulphuric acid (11).
Note 1.-Rubber stoppers absorb picric acid. They can be
cleaned by soaking in water and changing the water several
times. -
Note 2–The amount of filtrate collected in three-quarters
of an hour depends upon the grade of filter paper used. A rapid
filter paper must be used.
8
A STUDY OF THE CHAPIN AND POWICK METHOD (1)
FOR THE EXTRACTION OF THE ACID-
SOLUBLE PHOSPHORIC ACID.
Chapin and Powick extract the acid-soluble phosphoric acid
for two hours with 200 c. c. of water, 10 c. c. of 2.5 normal
hydrochloric acid and 5 to 8 grams of picric acid. Their method
was tested by varying the amounts of the reagents and the time
of extraction.
EFFECT OF VARYING THE AMOUNTS OF HYDROCHLORIC ACID.—
10 c.c. of 2.5 normal hydrochloric acid are equal to about 2 c. c.
of the concentrated acid. The amount of concentrated hydro-
chloric acid was, therefore, varied from 1 to 4 c. c. Each sample
of whole egg was divided into four 50-gram portions and each
sample of yolk was divided into four 25-gram portions. Each
portion of whole egg or yolk was extracted for two hours with
200 c. c. of hydrochloric acid solution, containing respectively
1, 2, 3 and 4 c. c. of concentrated hydrochloric acid and 8 grams
of picric acid. The results are given in Table 1.
TABLE I
EFFECT OF VARYING THE AMOUNTS OF
HYDROCHLORIC ACID
Hydrochloric acid, conc. 1 c. c. 2 c. c. 3 c. c. 4 c. c.
Grams Mg2P2O7 in 150 c. c. of filtrate
Sample
"f whole Egg 0122 0125 0128 0126
2 “ “ .0140 0140 .0144. .0147
3 “ “ 0145 0149 .0156 .0161
4 “ “ .0182 0181 .0185 0194
5 “ “ .0457 .0455 0449 .0459
6 Yolk .0167 .0171 .0172 .0183
7. “ .0161 .0170 0175 O177
8 “ .0160 0163 .0171 0175
9. “ .0146 .0148 0154 0157
10 “ .0158 .0170
EFFECT OF VARYING THE AMOUNTS OF PICRIC ACID.—Dupli-
cate determinations were made, one with 5 and the other with 10
grams of picric acid. Each sample of whole egg was divided into
two 50-gram portions and each sample of yolk was divided into
two 25-gram portions. Each portion of whole egg or yolk was
extracted for two hours with 200 c.c. of hydrochloric acid solu-
tion, containing 2 c. c. of concentrated hydrochloric acid, and with
5 and 10 grams of picric acid respectively. The results are shown
in Table II.
9 -
TABLE II
EFFECT OF PIRIC ACID
Picric Acid 5 Grams 10 Grams
Grams Mg2P2O7 in 150 c.c. of filtrate
Sample
No.
1 Whole Egg .O138 .0141
2 & & 4 & .0135 .0137
3 & & & & .0449 .0450
4. & & & & .0447 .0446
5 Yolk .0156 .0158
6 66 .0154 .0156
7 & & .0164 .0165
8 €6 .0161 - .0158
EFFECT OF TIME-Fifty-gram portions of whole egg and
25-gram portions of yolk were extracted with 200 c.c. of hydro-
chloric acid solution, containing 2 c. c. of concentrated hydro-
chloric acid, and 8 grams of picric acid. The time of extraction
was varied from one-half hour to forty-eight hours. The results
are given in Table III.
TABLE III.
EFFECT OF TIME
Hours % 1 1 2 3 4 |_24 48
Shaken by hand every Shaken
Shaken by machine 10 minutes occasionally
sºle Grams Mg2F2O7 in 150 c. c. of filtrate
i Whole Egg 0129 .01.38 .0361 0684
2 & & “ O139 .0148 .0309 .0505
3 & & & & .01.31 .01.36 -
4 & & & & .0140 .0145
5 & & “ .0120 .01.19
6 © & “ O105 0108
7 & & “ .01.15 .01.16
8 Yolk .0164. .0163
9 & & .0145 .014.5
10 “ .0153 .0156
11 & & .0138 0.139 .0148 .0152 0164
12 & & O157 .0159 .0163
13 a .0145 O150 .0156
DISCUSSION

The results in Table I show that the amount of acid-soluble
phosphoric acid extracted from eggs is affected by the amount
of hydrochloric acid used in the extraction. The difference in
magnesium pyrophosphate between two successive columns is
slight but when columns 1 and 4 are compared the difference is
quite marked. These results show that 1 c.c. of concentrated
10
hydrochloric acid is sufficient for the complete extraction of the
acid-soluble phosphoric acid because increasing the amount of
hydrochloric acid to 2 c.c. does not affect the results appreciably.
Table II shows that 5 and 10 grams of picric acid give the
same results. The filtration is much quicker with 10 than with
5 grams of picric acid. For this reason 10 grams of picric acid
would be more desirable than 5 grams. Since the effect of greater
amounts than 10 grams of picric acid was not investigated, it is
best to use a little less than 10 grams.
Table III shows that one-half hour and one hour extractions
give practically the same results, but if the process is continued
longer, more acid-soluble phosphoric acid is extracted.
The higher yield of acid-soluble phosphoric acid obtained when
more than 2 c.c. of concentrated hydrochloric acid was used, or
when the extraction was continued over one hour must be due
to the disintegration of organically combined phosphorus. There-
fore, the Chapin and Powick method of extraction was modified
as follows: The amount of hydrochloric acid was changed from
10 c.c. of 2.5 normal (about 2 c.c. of the concentrated acid) to
1 c.c. of concenrated hydrochloric acid and the time of extraction
was decreased to one hour.
RECOVERY OF ADDED PHOSPHORIC ACID
The modified Chapin and Powick method of extraction of
acid-soluble phosphoric acid was tested by determining the
amount of added phosphoric acid that can be recovered from
eggs. The phosphoric acid was determined in a solution of di-
sodium hydrogen phosphate by the official gravimetric method
(9). The acid-soluble phosphoric acid was estimated in a sample
of whole egg by the method described on page 8. A known
volume of the disodium hydrogen phosphate solution was added
to each of five aliquots of the sample of whole egg and the acid-
soluble phosphoric acid again determined. The results are given
in Table IV. .
TABLE IV.
Recovery of Added Phosphoric Acid
Sample No. 1 2 3 4. 5
Grams P2Os in 50 -
grams of eggs. .0153 .0153 .0153 .0153 .0153
Grams P.O.s added .0550 .0550 0550 .0550 .0550
Grams Total P.Os .0703 .0703 .0703 .0703 .0703
Grams P.O; found .0700 .0697 .0699 .0698 .0699
Per cent recovery. 99.57 99.15 99.43 99.29 99.43
Maximum recovery—99.57 per cent.
Minimum recovery—99.15 per cent.
Average recovery—99.37 per cent.
11
Table IV shows a practically complete recovery of phosphoric
acid added to eggs.
PLAN OF INVESTIGATION
To find the normal variations of the acid-soluble phosphoric
acid in edible whole egg and yolk, twenty-five samples of each
were selected. They varied from eggs one day old to the lowest
grade obtainable in groceries in the Spring. To find the maxi-
mum amount of acid-soluble phosphoric acid that could be per-
mitted in edible whole egg and yolk, ten samples of each were
selected from weak eggs with slightly stuck yolks which could
be set free by a quick twist of the egg. These eggs are edible
according to Pennington, Jenkins and Betts (12). To determine
whether the increase in the acid-soluble phosphoric acid in eggs
is proportional to the degree of decomposition, spots, white rots
and black rots were selected. The eggs were candled and
examined out of the shell as described by Pennington, Jenkins
and Betts (12). Each sample of whole egg consisted of two eggs
and each sample of yolk consisted of the yolks of three eggs.
Cook (3) states the following: “Eggs in storage for one year
show a loss of weight equivalent to 10 per cent of the total weight,
which loss is largely water from the whites.” Greenlee (13) re-
ports a loss of moisture in the white and a gain in the yolk in
cold storage. Since whole egg loses moisture and yolk gains
moisture on standing, results on stale eggs cannot be compared
with those on fresh eggs, unless calculated to a dry basis.
ACID-SOLUBLE PHOSPHORIC ACID AND WATER IN
WHOLE EGG.
1. Whole Egg of Good Quality.
TABLE V.
A. One Day Old.
Water Acid-Soluble PaOs
% Milligrams per 100 Grams
No. & Original
Material Dry Basis
1 . . . . . . . . . . . . . . . . . . . . . . . 72.94 20.9 77.2
2 . . . . . . . . . . . . . . . . . . . . . . . 75.40 23.5 95.5
3 . . . . . . . . . . . . . . . . . . . . . . . 73.00 22.9 84.8
4 . . . . . . . . . . . . . . . . . . . . . . . 72.31 21.3 76.9
5 . . . . . . . . . . . . . . . . . . . . . . . 74.18 21.4 82.8
Maximum . . . . . . . . . . . . . . . . . 75.40 23.5 95.5
Minimum . . . . . . . . . . . . . . . . . 72.31 20.9 76.9
Average . . . . . . . . . . . . . . . . . . . . 73.57 22.0 83.4 +5.4
TABLE VI.
B. Highest Grade Obtainable in Groceries in the Spring.
Water Acid-Soluble P.O;
% Milligrams per 100 Grams
No. Original
Material Dry Basis
1 . . . . . . . . . . . . . . . . . . . . . . . 73.39 22.4 84.2
2 . . . . . . . . . . . . . . . . . . . . . . . 72.89 22.9 84.5
3 . . . . . . . . . . . . . . . . . . . . . . . 73.93 24.0 92.1
4 . . . . . . . . . . . . . . . . . . . . . . . 74.69 21.8 86.1
5 . . . . . . . . . . . . . . . . . . . . . . . 73.31 23.3 87.3
6 . . . . . . . . . ... tº e º e º e º e s tº e º 'º e 73.06 22.1 82.0
7 . . . . . . . . . . . . . . . . . . . . . . . 73.63 23.2 88.0
8 . . . . . . . . . . . . . . . . . . . . . . . 72.59 24.1 87.9
9 . . . . . . . . . . . . . . . . . . . . . . . 73.62 20.1 76.2
10 . . . . . . . . . . . . . . . . . . . . . . . 72.34 25.5 92.2
Maximum . . . . . . . . . . . . . . . . . 74.69 25.5 92.2
Minimum . . . . . . . . . . . . . . . . . 72.34 20.1 76.2
Average . . . . . . . . . . . . . . . . . . . 73.35 22.9 86.0 +3.5
TABLE VII.
C. Lowest Grade Obtainable in Groceries in the Spring.
Water Acid-Soluble P.O.
% Milligrams per 100 Grams
No. Original
- Material Dry Basis
1 . . . . . . . . . . . . . . . . . . . . . ... 71.21 23.8 82.7
2 . . . . . . . . . . . . . . . . . . . . . . . 71.69 26.5 93.6
3 . . . . . . . . . . . . . . . . . . . . . . . 73.19 19.3 72.0
4 . . . . . . . . . . . . . . . . . . . . . . . 72.43 22.7 82.3
5 . . . . . . . . . . . . . . . . . . . . . . . 71.85 25.1 89.2
6 . . . . . . . tº e s e e s e e e s e e s e e º 'º 72.68 19.9 72.8
7 . . . . . . . . . . . . . . . . . . . . . . . 73.88 21.4 81.9
8 . . . . . . . . . . . . . . . . • - - - - - 72.98 20.5 75.9
9 . . . . . . . . . . . . . . . . . . . . . . . 71.40 21.9 76.6
10 . . . . . . . . . . . . . . . . . . . . . . . 72.63 21.2 77.5
Maximum . . . . . . . . . . . . . . . . . 73.88 26.5 93.6
Minimum . . . . . . . . . . . . . . . . . . 71.21 19.3 72.0
Average . . . . . . . . . . . . . . . . . . . 72.39 22.2 80.5 +5.5
TABLE VIII.
Summary of Results on Fresh Eggs of Good Quality
(Tables V, VI and VII).
Water Acid-Soluble P.O;
% Milligrams per 100 Grams
Original
Material Dry Basis
Maximum . . . . . . . . . . . . . . . . . 75.40 26.5 95.5
Minimum . . . . . . . . . . . . . . . . . . 71.21 19.3 72.0
Average . . . . . . . . . . . . . . . . . . . 73.01 22.5 83.3 +5.3
TABLE IX.
2. Whole Egg. Yolk Stuck to the Shell But Can Be Set Free by
a Quick Twist of the Egg.
No. Water Acid-Soluble P.Os
% Milligrams per 100 Grams
Original
Material Dry Basis
1 . . . . . . . . . . . . . . . . . . . . . . . 71.91 28.8 102.5
2 . . . . . . . . . . . . . . . . . . . . . . . 71.97 26.4 94.2
3 . . . . . . . . . . . . . . . . . . . . . . . 72.34 25.2 91.1
4 . . . . . . . . . . . . . . . . . . . . . . . 72.50 25.0 90.9
5 . . . . . . . . . . . . . . . . . . . . . . . 71.90 25.8 91.8
6 . . . . . . . . . . . . . . . . . . . . . . . 70.34 28.1 94.7
7 . . . . . . . . . . . . . . . . . . . . . . . 70.64 28.1 95.7
8 . . . . . . . . . . . . . . . . . . . . . . . 72.08 26.2 93.8
9 . . . . . . . . . . . . . . . . . . . . . . . 71.66 25.4 89.6
10 . . . . . . . . . . . . . . . . . . . . . . . 72.04 27.4 98.0
Maximum . . . . . . . . . . . . . . . . . 72.50 28.8 102.5
Minimum . . . . . . . . . . . . . . . . . . 70.34 25.0 89.6
Average . . . . . . . . . . . . . . . . . . . 71.74 26.6 94.2 +2.8
TABLE X.
3. Whole Egg. Held in Cold Storage Eleven Months.
No. Water Acid-Soluble P.O;
% Milligrams per 100 Grams
Original
Material Dry Basis
1 . . . . . . . . . . . . . . . . . . . . . . . 70.63 28.8 98.1
2 . . . . . . . . . . . . . . . ... • * * * * * * 71.66 26.1 92.1
3 . . . . . . . . . . . . . . . . . . . . . . . 71.00 27.3 94.1
4 . . . . . . . . . . . . . . . . . . . . . . . 71.36 28.8 100.6
5 . . . . . . . . . . . . . . . . . . . . . . . 71.54 29.1 102.2
6 . . . . . . . . . . . . . . . . . . . . . . . 72.21 28.7 103.3
7 . . . . . . . . . . . . . . . . . . . . . . . 71.74 31.9 112.9
Maximum . . . . . . . . . . • • • - - - - 72.21. 31.9 112.9
Minimum . . . . . . . . . . . . . . . . . . 70.63 26.1 92.1
Average . . . . . . . . . . * e o e s e e s • 71.45 28.7 100.5 +4.9
TABLE XI.
4. Whole Egg. Yolk Stuck to the Shell But Can Be Set Free
by Several Quick Twists of the Egg.
Water Acid-Soluble P.O.
% Milligrams per 100 Grams
No. Original
Material Dry Basis
! . . . . . . . . . . . . . . . . . . . . . . . 68.49 30.1 95.5
2 . . . . . . . . . . . . . . . . . . . . . . . 69.07 30.9 99.9
3 . . . . . . . . . . . . . . . . . . . . . . . 69,25 35.3 114.8
* . . . . . . . . . . . . . . . . . . . . . . . 70,09 31.8 106.3
5 . . . . . . . . . . . . . . . . . . . . . . . 67.85 34.0 105.8
6 . . . . . . . . . . . . . . . . . . . . . . . 70.35 30.0 101.2
7 . . . . . . . . . . . . . . . . . . . . . . . 68.86 33.5 107.6
8 . . . . . . . . . . e e s e s e º e e s a e e 70.52 26.2 88.9
9 . . . . . . . . . . . . . . . . . . . . . . . 72.54 28.4 103.4
10 . . . . . . . . . . . . . . . . . . . . . . . 72.56 24.2 88.2
Maximum . . . . . . . . . . . . . . . . . 72.56 35.3 114.8
Minimum . . . . . . . . . . . . . . . . . . 68.49 24.2 88.2
Average . . . . . . . . . . . . . . . . . . . 69.96 30.4 101.2 +6.4
TABLE XII.
5. Inedible Whole Egg. Heavy Spots. Yolk Stuck to the Shell
and Cannot be Set Free by Twisting the Egg.
Water Acid-Soluble P.O;
% Milligrams per 100 Grams
No. Original
Material Dry Basis
! . . . . . . . . . . . . . . . . . . . . . . . 71.30 28.8 100.0
2 . . . . . . . . . . . . . . . . . . . . . . . 70.78 28.7 98.2
3 . . . . . . . . . . . . . . . ... e. e. e. e. e. e. e. e. 72.22 29.4 105.8
4 . . . . . . . . . . . . . . . . . . . . . . . 70.22 36.1 121.0
5 . . . . . . . . . . . . . . . . . . . . . . . 67.78 32.6 101.2
6 . . . . . . . . . . . . . . . . . . . . . . . 69.73 29.6 97.8
7 . . . . . . . . . . . . . . . . . . . . . . . 63.60 46.4 127.5
8 . . . . . . . . . . i e o e o e s • * * * * ... 63.83 41.2 113.9
9 . . . . . . . . . . . ... • * * * : * * * * * * * * 67.66 34.6 107.0
Maximum . . . . . . . . . . * c e e º e o e 72.22 46.4 127.5
Minimum . . . . . . . . . . . . . . . . . . 63.60 28.7 97.8
Average . . . . . . . . . . . . . . . . . . . 68.57 34.2 1080+7.6
TABLE XIII.
6. Inedible Whole Egg. Decomposed Frozen Eggs. Putrid Odor.
Water Acid-Soluble P2Cs
% Milligrams per 100 Grams
No. Original
Material Dry Basis
1 . . . . . . . . . . . . . . . . . . . . . . . 70.00 46.2 154.0
2 . . . . . . . . . . . . . . . . . . . . . . . 69.02 52.1 168.2
3 . . . . . . . . . . . . . . . . . . . . . . . 69.24 54.6 177.5
4 . . . . . . . . . . . . . . . . . . . . . . . 70.41 44.8 151.4
5 . . . . . . . . . . . . . . . . . . . . . . . 69.45 51.6 168.9
Maximum . . . . . . . . . . . . . . . . . 70.41 54.6 177.5
Minimum . . . . . . . . . . . . . . . . . . 69.02 44.8 151.4
Average . . . . . . . . . . . . . . . . . . . 69.62 49.9 164.0
TABLE XIV.
7. Inedible Whole Egg. White Rots.
2 Water Acid-Soluble P2Cs
% Milligrams per 100 Grams
No. Original
Material Dry Basis
! . . . . . . . . . . . . . . . . . . . . . . . 70,07 73.0 243.9
2 . . . . . . . . . . . . . . . . . . . . . . . 68.63 92.6 295.2
3 . . . . . . . . . . . . . . . . . . . . . . . 63.19 45.5 123.6
4 . . . . . . . . . . . . . . . . . . . . . . . 70,03 70.6 235.6
Maximum . . . . . . . . . . . . . . . . . 70,07 92.6 295.2
Minimum . . . . . . . . . . . . . . . . . . 63.19 45.5 123.6
Average . . . . . . . . . . . . . . . . . . . 67.98 70.4 224.6
!
TABLE XV.
8. Inedible Whole Egg. Black Rots.
Water Acid-Soluble P.O;
%. Milligrams per 100 Grams
No. Original Dry Basis
Material
1 . . . . . . . . . . . . . . . . . . . . . . . 64.41 229.4 644.6
2 . . . . . . . . . . . . . . . . . . . . . . . 69.55 1427 468.6
3 . . . . . . . . . . . . . . . . . . . . . . . 73.13 178.1 662.8
4 . . . . . . . . . . . . . . . . . . . . . . . 74.51 184.0 721.9
Maximum . . . . . . . . . . . . . . . . . 74.51 229.4 721.9
Minimum . . . . . . . . . . . . . . . . . 64.41 142.7 468.6
Average . . . . . . . . . . . . . . . . . . . 70.40 183.6 624.5
ACID-SOLUBLE PHOSPHORIC ACID AND
WATER IN YOLK.
1. Yolk From Fresh Eggs of Good Quality.
TABLE XVI.
A. Yolk From Eggs One Day Old.
No. Water Acid-Soluble P.Os
% Milligrams per 100 Grams
Migin
& Material Dry Basis
1 . . . . . . . . . . . . . . . . . . . . 1... 47.95 51.6 99.1
2 . . . . . . . . . . . . . . . . . . . . . . . 47.41 49.4 93.9
3 . . . . . . . . . . . . . . . . . . . . . . . 47.16 50.4 95.4
4 . . . . . . . . . . . . . . . . . . . . . . . 48.06 58.1 111.9
5 . . . . . . . . . . . . . . . . . . . ... . 47.24 54.0 102.4
Maximum . . . . . . . . . . . . . . . . . 48.06 58.1 111.9
Minimum . . . . . . . . . . . . . . . . . . 47.16 49.4 93.9
Average . . . . . . . . . . . . . . . . . . . 47.56 52.7 100.5 +5.3
TABLE XVII.
B. Yolk From the Highest Grade Eggs Obtainable in Groceries
in the Spring.
No. - Water Acid-Soluble P.O;
- % Milligrams per 100 Grams
T1
Material Dry Basis
1 . . . . . . . . . . . . . . . . . . . . . . . 49.01 520 102.0
2 . . . . . . . . . . . . . . . . . . . . . . . A9.67 50.2 99.7
3 . . . . . . . . . . . . . . . . . . . . . . . 49.10 53.8 105.7
4 . . . . . . . . . . . . . . . . . . . . . . . 49.48 62.1 122.9
5 . . . . . . . . . . . . . . . . . . . . . . . 49.64 54.6 108.4
6 . . . . . . . . . . . . . . . . . . . . . . . 50.06 56.8 113.7
7 . . . . . . . . . . . . . . . . . . . . . ... 50.15 55.3 110.9
8 . . . . . . . . . . . . . . . . . . . . . . . 50.42 53.2 107.3
9 . . . . . . . . . . . . . . . . . . . . . . . 49.48 53.5 105.9
10 . . . . . . . . . . . . . . . . . . . . . . . . 49.34 51.3 101.3
Maximum . . . . . . . . . . . . . . . . . 50.42 62.1 122.9
Minimum . . . . . . . . . . . . . . . . . . 49.01 50.2 99.7
Average . . . . . . . . . . . . . . . . . . . 49.64 54.3 107.8 +5.0
TABLE XVIII
C. Yolk From the Lowest Grade Eggs Obtainable in
in the Spring.
Water Acid-Soluble P.O.
% Milligrams per 100 Grams
No. Original
. Material Dry Basis
1 . . . . . . . . . . . . . . . . . . . . . . . 50.69 49.9 101.2
2 . . . . . . . . . . . . . . . . . . . . . . . 50.20 58.9 118.3
3 . . . . . . . . . . . . . . . . . . . . . . . 49.87 52.4 108.1
4 . . . . . . . . . . . . . . . . . . . . . . . 48.91 56.3 110.2
5 . . . . . . . . . . . . . . . . . . . . . . . 48.52 56.3 109.4
6 . . . . . . . . . . . . . . . . . . . . . . . 50.02 49.9 99.8
7 . . . . . . . . . . . . . . . . . . . . . . . 49.35 52.8 104.2
8 . . . . . . . . . . . . . . . . . . . . . . . 49.52 48.8 96.7
9 . . . . . . . . . . . . . ... e. e. e º 'º - © e º º 49.70 51.0 101.4
10 . . . . . . . . . . . . . . . . . . . . . ... 50.06 44.8 89.7
Maximum . . . . . . . . . . . . . . . . . 50.69 58.9 118.3
Minimum . . . . . . . . . . . . . . . . . . 48.52 44.8 89.7
Average . . . . . . . . . . . . . . . . . . . 49.68 52.1 103.9 +5.1
TABLE XIX.
Summary of Results on Yolk From Fresh Eggs of Good Quality
(Tables XVI, XVII and XVIII).
Water Acid-Soluble P.O.
% Milligrams per 100 Grams
Original
Material Dry Basis
Maximum . . . . . . . . . . . . . . . . . 50.69 62.1 122.9
Minimum . . . . . . . . . . . . . . . . . 47.16 44.8 89.7
Average . . . . . . . . . . . . . . . . . . . 49.24 53.1 104.8 +6.0
18
TABLE XX.
2. Yolk From Stale Eggs. Yolk Stuck to the Shell But Can Be
Set Free by a Quick Twist of the Egg.
Water Acid-Soluble P.Os
% Milligrams per 100 Grams
Original
Material Dry Basis
! . . . . . . . . . . . . . . . . . . . . . . . 51.39 53.4 109.9
2 . . . . . . . . . . . . . . . . . . . . . . . 51.73 59.2 122.6
3 . . . . . . . . . . . . . . . . . . . . . . . 51.01 59.6 121.7
4 . . . . . . . . . . . . . . . . . . . . . . . 50.88 55.2 112.4
5 . . . . . . . . . . . . . . . te e s a e s • * 51.12 47.6 97.4
6 . . . . . . . . . . . . . . . . . . . . . . . 50.71 47.9 97.2
7 . . . . . . . . . . . . . . . . . . . . . . . 51.45 53.4 110.0
8 . . . . . . . . . . . . . . . . . . . . . . . 51.17 55.6 113.9
9 . . . . . . . . . . . . . . . . . . . . . . . 52.43 52.4 110.2
10 . . . . . . . . . . . . . . . . . . . . . . . 52.49 52.7 110.9
Maximum . . . . . . . . . . . . . . . . . 52.49 59.6 122.6
Minimum . . . . . . . . . . . . . . . . . 50.71 47.6 97.2
Average . . . . . . . . . . . . . . . . . . . 51.44 53.7 110.6 +5.7
TABLE XXI.
3. Yolk From Stale Eggs. Yolk. Stuck to the Shell But Can Be
Set Free by Several Quick Twists of the Egg.
Water Acid-Soluble P.O;
% Milligrams per 100 Grams
No. Original
Material Dry Basis
1 . . . . . . . . . . . . . . . . . . . . . . . 52.70 54.1 114.4
2 . . . . . . . . . . . . . . . . . . . . . . . 51.46 54.7 112.7
3 . . . . . . . . . . . . . . . . . . . . . . . 51.29 55.8 114.6 .
4 . . . . . . . . . . . . . . . . . . . . . . . 52.33 50.8 106.6
5 . . . . . . . . . . . . . . . . . . . . . . . 53.03 53.3 113.5
6 . . . . . . . . . . . . . . . . . . . . . . . 52.75 56.9 120.4
7 . . . . . . . . . . . . . . . . . . . . . . . 51.59 54.3 112.2
8 . . . . . . . . . . . . . . . . . . . . . . . 52.71 56.0 118.4
Maximum . . . . . . . . . . . . . . . . . 53.03 56.9 120.4
Minimum . . . . . . . . . . . . . . . . ... 51.29 50.8 106.6
Average . . . . . . . . . . . . . . . . . . . 52.23 54.5 114.1 +2.9
TABLE XXII.
4. Yolk From Eggs Which Were Held in Cold Storage
Eleven Months.
wº
No. Original
Material
tº º º e º e º 'º e º e º e e º e º e e º ſº e e 52.97 66.4
• e s e s is e e e s e a e e e s t e º e e e s e 52.83 55.5
tº e º e º ºs e e º 'º e º e º e º tº e º te e º e 53.90 57.8
4 . . . . . . . . . . . . . . . . . . . . . . . 53.89 56.7
e e º te e e º te e º e º e a e º e º º e º e e 54.55 57.4
tº e º 'º e º 'º º e º e º ºs e º e º e º º e º e 54.30 59.2
Maximum . . . . . . . . . . . . . . . . . 54.55 66.4
Minimum . . . . . . . . . . . . . . . . . . 52.83 55.6
Average . . . . . . . . . . . . . . . . . . . 53.74. 58.8
TABLE XXIII
Acid-Soluble P.Os
Milligrams per 100 Grams
Dry Basis
141.2
117.7
125.4
123.0
126.3
129.5
141.2
117.7 -
127.2 +5.5
SUMMARY OF RESULTS ON ACID-SOLUBLE PHOS-
PHORIC ACID IN WHOLE EGG AND YOLK
:
%
be set free by twisting the egg. . .
the egg
Whole Egg
Acid-Soluble P2O5 mgs. per
Min.
Good quality 72.0
Yolk stuck to the shell but can be
set free by a quick twist of the egg
Held in cold storage eleven months
Yolk stuck to the shell but can be
set free by several quick twists of
the egg
Yolk stuck to the shell and cannot
89.6
92.1
e e s e e s tº e s e e º e º e s e e g º e º e 88.2
97.8
Decomposed frozen 151.4
White rots
Black rots
e e º ºs e e º e e º 'º e
• • • • * * * * * * * * * * * * * * * *
Good quali
Yolk stuck to the shell but can be
set free by a quick twist of the egg 97.2
Yolk stuck to the shell but can be
set free by several quick twists of
Held in cold storage eleven months 1177
20
106.6
100 grams, dry basis
Max.
95.5
102.5
112.9
114.8
127.5
177.5
295.2
721.9
122.9
122.6
120.4
141.2
Average
83.3 + 5.3
94.2 + 2.8
100.5 + 4.9
101.2 + 6.4
108.0 + 7.6
164.0
224.6
624.5
104.8 + 6.0
110.6 = 5.7
114.
1 + 29
127.2 + 5.5
DISCUSSION
Water in Whole Egg and Yolk.
The water content of whole egg was found to vary from
75.40 per cent (Table V) to 63.19 per cent (Table XIV). One
day old eggs gave an average of 73.57 per cent of water. Eggs
which were held in cold storage for eleven months gave an
average of 71.45 per cent of water. The water content of yolk
was found to vary from 47.16 per cent (Table XVI) to 54.55
per cent (Table XXII). Yolk from eggs one day old gave an
average of 47.56 per cent of water. Yolk from eggs which were
held in cold storage for eleven months gave an average of 53.74
per cent of water. These results show that whole egg loses mois-
ture and yolk gains moisture on standing. Therefore, the acid-
Soluble phosphoric acid must be calculated on a dry basis.
Acid-Soluble Phosphoric Acid in Whole Egg.
In Table VIII are shown 25 samples of fresh eggs of good
quality. These eggs were divided into three grades: one day
old, the highest, and the lowest grades obtainable in groceries in
the Spring. As a rule, only fresh eggs are sold in groceries in
the Spring. Even the lowest grade eggs were of good quality.
Table V shows that the acid-soluble phosphorus pentoxide in
five samples of eggs one day old varies from 76.9 to 95.5 milli-
grams per 100 grams on a dry basis, and the average is 83.4 milli-
grams. The average deviation from the arithmetic mean is + 5.4.
The variations in the amount of acid-soluble phosphorus pen-
toxide in 10 samples of fresh eggs of the highest grade obtainable
in groceries in the Spring are shown in Table VI. The minimum
is 76.2, the maximum is 92.2, and the average is 86.0 milligrams
per 100 grams on a dry basis. The average deviation from the
arithmetic mean is + 3.5. Table VII shows that the acid-soluble
phosphorus pentoxide in 10 samples of fresh eggs of the lowest.
grade obtainable in groceries in the Spring varies from 72.0 to
93.6 milligrams per 100 grams on a dry basis, and the average is
80.5 milligrams. The average deviation from the arithmetic mean
is + 5.5. As stated above, only eggs of good quality were used
in this series of 25 samples. If the increase in the amount of
acid-soluble phosphoric acid in eggs is to be used as a test for
decomposition, the lower grade eggs should not give higher re-
sults than the higher grade eggs, unless decomposition has set in.
The results obtained on the three grades of eggs do not differ ap-
preciably. A summary of the results of Tables V, VI and VII
on 25 samples of fresh eggs of good quality is given in Table
VIII. The minimum is 72.0, the maximum is 95.5, and the
21
average is 83.3 milligrams per 100 grams on a dry basis. The
average deviation from the arithmetic mean is + 5.3.
In Table IX are shown 10 samples of stale eggs. Fresh eggs
were allowed to stand until the yolks stuck to the shells but could
be set free by a quick twist of the eggs. These eggs are con-
sidered edible (12). The acid-soluble phosphorous pentoxide in
these eggs varies from 89.6 to 102.5 milligrams per 100 grams
on a dry basis, and the average is 94.2 milligrams. The average
deviation from the arithmetic mean is + 2.8. The minimum,
maximum and the average results are higher than those obtained
on eggs of good quality (Table VIII). These results show that
after decomposition has set in, as shown by candling and physical
examination out of the shell, the acid-soluble phosphoric acid is
increased.
Table X shows 7 samples of eggs which were held in cold
storage for eleven months. The condition of these eggs was as
follows: the air spaces were movable, the yolks separated from
the whites with great difficulty, the whites were very thin and
slightly colored yellow and the eggs had a perceptible odor. The
acid-soluble phosphorus pentoxide in these eggs varies from 92.1
to 112.9 milligrams per 100 grams on a dry basis, and the average
is 100.5 milligrams. The average deviation from the arithmetic
mean is + 4.9.
In Table XI are shown 10 samples of eggs of a doubtful
nature. These eggs cannot be classed as edible or inedible. The
eggs of this series were allowed to stand until the yolks stuck
to the shells but could be set free by several quick twists of the
eggs. As a rule, a candler does not twist an egg before the
candle more than two or three times. The average candler might
pass some of the eggs of this series as edible, but not all. The
acid-soluble phosphorus pentoxide in these eggs varies from
88.2 to 114.8 milligrams per 100 grams on a dry basis, and the
average is 101.2 milligrams. The average deviation from the
arithmetic mean is + 6.4. The minimum, maximum, and the
average results are higher than those obtained on eggs of good
quality (Table VIII). The maximum and the average results
are higher than those obtained on eggs the yolks of which stuck
to the shells but could be set free by a single quick twist of the
eggs (Table IX). The difference in age between eggs of Table
IX and Table XI may be only a few days.
Table XII shows nine samples of heavy spots. The yolks
of these eggs were stuck to the shells and could not be set free
by twisting the eggs. This grade of eggs is considered inedible.
The acid-soluble phosphorus pentoxide was found to vary from
97.8 to 127.5 milligrams per 100 grams on a dry basis, and the
average is 108.0 milligrams. The average deviation from the
arithmetic mean is + 7.6. On further decomposition, spots are
22
changed to white rots and these in turn are changed to black rots.
Table XIV shows four samples of white rots. The acid-soluble
phosphorus pentoxide in these eggs varies from 123.6 to 295.2
milligrams per 100 grams on a dry basis, and the average is 224.6
milligrams. Table XV shows four samples of black rots. The
acid-soluble phosphorus pentoxide in these eggs varies from
468.6 to 721.9 milligrams per 100 grams on a dry basis, and the
average is 624.5 milligrams.
In Table XXIII is given a summary of results on eight grades
of whole egg used in this investigation. Excluding numbers 3
and 6, this table is arranged in the order of the gradual decom-
position of eggs. The results show a progressive increase in the
acid-soluble phosphoric acid from an average of 83.3 milligrams
of phosphorus pentoxide per 100 grams in eggs of good quality
to an average of 624.5 milligrams in black rots.
Acid-Soluble Phosphoric Acid in Yolk
In Table XIX are shown 25 samples of yolk from fresh eggs
of good quality. As in the case of whole egg, the yolks of this
series also were divided into three grades: from eggs one day old,
from the highest, and from the lowest grades of eggs obtainable
in groceries in the Spring. The eggs of this series were of the
same quality as those described in Table VIII. Table XVI
shows five samples of yolk from eggs one day old. The acid-
soluble phosphorus pentoxide in these yolks was found to vary
from 93.9 to 111.9 milligrams per 100 grams on a dry basis, and
the average is 100.5 milligrams. The average deviation from the
arithmetic mean is + 5.3. The variation in the amount of acid-
soluble phosphorus pentoxide in 10 samples, of yolk from the
highest grade eggs obtainable in groceries in the Spring is shown
in Table XVII. The minimum is 99.7, the maximum is 1229,
and the average is 107.8 milligrams per 100 grams on a dry basis.
The average deviation from the arithmetic mean is + 5.9. Table
XVIII shows that the acid-soluble phosphorus pentoxide. in 10
samples of yolk from eggs of the lowest grade obtainable in
groceries in the Spring varies from 89.7 to 118.3 milligrams per
100 grams on a dry basis, and the average is 103.9 milligrams.
The average deviation from the arithmetic mean is, F 5.1. The
results obtained on these three grades of yolk...do not differ
appreciably. A summary of the amount of acid-soluble phos-
phorus pentoxide found in 25 samples of yolk from fresh eggs
of good quality (Tables XVI, XVII and XVIII) is given in
Table XIX. The minimum is 89.7, the maximum is 1229, and
the average is 104.8 milligrams per 100 grams on a dry basis.
The average deviation from the arithmetic mean is + 6. Of the
25 samples of yolk, 23 contain less than 114 milligrams.
23
Table XX shows 10 samples of yolk from eggs the yolks of
which stuck to the shells but could be set free by a quick twist
of the eggs. These eggs were of the same grade as those de-
scribed in Table IX. The acid-soluble phosphorus pentoxide was
found to vary from 97.2 to 122.6 milligrams per 100 grams on a
dry basis, and the average is 110.6 milligrams. The average dev-
iation from the arithmetic mean is + 5.7. The minimum and the
average results are higher than those obtained on yolk from eggs
of good quality (Table XIX), but the maximum is the same.
In Table XXI are shown 8 samples of yolk from eggs of the
same grade as those described in Table XI. The eggs of this
series were allowed to stand until the yolks stuck to the shells but
could be set free by several quick twists of the eggs. The
acid-soluble phosphorus pentoxide in these yolks varies from 106.6
to 120.4 milligrams per 100 grams on a dry basis, and the average
is 114.1 milligrams. The average deviation from the arithmetic
mean is + 2.9. The minimum and the average results are higher
than those obtained on yolks from eggs of good quality (Table
XIX), but the maximum is lower. .
Table XXII shows 6 samples of yolk from eggs which were
held in cold storage for eleven months. These eggs were of the
same quality as those described in the discussion of Table X. The
acid-soluble phosphorus pentoxide was found to vary from 117.7
to 141.2 milligrams per 100 grams on a dry basis, and the average
is 127.2 milligrams. The average deviation from the arithmetic
mean is + 5.5. In these yolks the minimum, maximum and the
average results are higher than those obtained in yolk from eggs
of good quality (Table XIX).
24
SUMMARY AND CONCLUSIONS
1. Chapin and Powick's method for the extraction of the acid
soluble phosphoric acid from eggs was modified as follows: the
amount of hydrochloric acid was changed from 10 c. c. of 2.5
normal to 1 c.c. of concentrated acid in 200 c.c. of water and the
time of extraction was decreased to one hour.
2. Whole egg was found to lose moisture and yolk was found
to gain moisture on standing. Therefore, the acid-soluble phos-
phoric acid must be calculated on a dry basis, to secure comparable
results. -
3. The amount of acid-soluble phosphorus pentoxide in 25
Samples of fresh eggs of good quality was found to vary from
72 to 95.5 milligrams per 100 grams on a dry basis. These eggs
were divided into three grades: one day old, the highest, and the
lowest grades obtainable in groceries in the Spring. The results
obtained on these three grades of whole egg do not differ appre-
ciably, showing that whatever the age of an egg, as long as candling
and physical examination out of the shell do not show any signs
of decomposition, the amount of acid-soluble phosphoric acid is
not increased. &
4. The amount of acid-soluble phosphorus pentoxide in 25
Samples of yolk from eggs of good quality was found to vary
from 89.7 to 122.9 milligrams per 100 grams on a dry basis. The
yolks of this series were divided into three grades: from eggs one
day old, from the highest, and the lowest grades of eggs obtainable
in groceries in the Spring. The results obtained on these three
grades of yolk do not differ appreciably.
5. The amount of acid-soluble phosphoric acid in eggs was
found to increase on decomposition, the increase depending upon
the degree of deterioration.
6. This investigation was carried out on small samples in
order to bring out the greatest variations possible in the amount
of acid-soluble phosphoric acid in whole egg and yolk. Each
sample of whole egg consisted of two eggs and each Sample of
yolk consisted of the yolks of three eggs.
7. The results obtained in this investigation warrant the fur-
ther study of the acid-soluble phosphoric acid in eggs on a com-
mercial scale. -
25
References
* jºin R. M., and Powick, W. C., J. Biol. Chem. XX, p. 97,
915.
Sherman, H. C., Food Products, New York, 1916, p. 137.
Cook, F. C., Bulletin No. 115, Bureau of Chemistry, United
States Department of Agriculture, 1908.
Atwater, W. O., and Bryant, A. P., Bulletin No. 28 (Revised
Edition) United States Department of Agriculture, 1906.
. Leach, A. E., Food Inspection and Analysis, New York, 4th
Edition, 1920, Page 271.
. König, J., Chemie der Menschlichen Nahrungs-und Genuss-
mittel, Berlin, 4th Edition, 1904, Vol. II, p. 575.
Halliburton, W. D., Handbook of Physiology, Philadelphia,
11th Edition, 1913, p. 429.
MacLean, H., Lecithin and Allied Substances, The Lipins,
London, 1918, p. 17.
Official and Tentative Methods of Analysis of the Association
of Official Agricultural Chemists, Washington, 1920, p. 1.
Redfield, H. W., Bulletin No. 846, Bureau of Chemistry,
United States Department of Agriculture, 1920.
. Pharmacopoeia of the United States of America, 9th Edition,
1916, p. 471. -
. Pennington, M. E., Jenkins, M. K., and Betts, H. M., Bulletin
No. 565. Bureau of Chemistry, U. S. Dept. of Agriculture,
1918.
. Greenlee, A. D., Circular No. 83. Bureau of Chemistry, United
States Department of Agriculture, 1911.
1
3
Biographical
Louis Pine was born in Russia on May 20, 1887. He entered
Cooper Union Five-Year Night Course in Chemistry in 1908, and
was graduated with a diploma in chemistry in 1913. He studied
in the Polytechnic Institute, Brooklyn, from 1913 to 1916, and
was graduated with the degree of Bachelor of Science in Chem-
istry in 1916. During 1916-1917 he pursued post-graduate studies
in biological chemistry and physiology in Columbia University, and
in 1917, received the degree of Master of Arts. He served in the
United States Army from September, 1917, to August, 1919.
After discharge from the Army he returned to Columbia Univer-
sity as a candidate for the degree of Doctor of Philosophy in 1920.
Publication
“Aluminum in the Blood of Man Following the Prolonged In-
gestion of Food Containing Aluminum.”
By Louis Pine and Paul E. Howe.
In press—Biochemical Bulletin.
26
UNIVERSITY OF MICHIGAN
|||||||
3 9015 08038 3592 -
|