jan. 15,1925 Occurrence of Copper, etc., in Soils, Plants, and Animals 195 
Table I.— Metals found in vegetable substances , expressed in parts per million 
of moisture-free material ° 
Material 
Copper 
Iron 
Mangan¬ 
ese (15) 
Zinc 
Nickel 
Cobalt 
Bluegrass {Poa pratensis) .. 
Soybean leaves..... 
Soybean seeds.. 
Wheat bran.. 
7.5 
8.0 
12.0 
16.0 
46.0 
Trace 
10.0 
Trace 
7.0 
Trace 
336.0 
336.0 
70.0 
210.0 
270.0 
24.0 
270.0 
30.0 
168.0 
3.0 
30.0 
160.0 
32.5 
125.0 
150.0 
10.0 
40.0 
16.0 
100.0 
10.0 
28.0 
110.0 
18.4 
75.0 
160.0 
Trace 
103.0 
Trace 
70.0 
Trace 
Trace 
Trace 
3.92 
Trace 
Trace 
Trace 
Wheat germs... 
Patent flour. ___ 
Corn germs__ 
— 
Corn endosperm... 
Rice polishings... 
Polished rice__ 
a The data in Table I, except those for manganese, were obtained by methods described by Scott (U), 
using the hydrochloric acid solution of the ash from 100 gm. of air-dried material, except the soybean seeds, 
of which 500 gm. were used. Manganese was determined by the periodate method {15) in a separate portion 
of 10 gm. of material. 
Table II.— Metals found in animal substances; expressed in parts per million of 
the moisture-free material 
Material 
Copper 
Iron 
Manganese 
Zinc 
Lean meat of ox_____ 
0.4 
225.0 
Trace 
15.0 
Liver of same ox______ 
75.0 
308.0 
15.0 
112.0 
Liver of calf one week old_ 
345.0 
168.0 
14.0 
122.5 
Blood of same calf.__ 
8.0 
1,720.0 
Trace 
32.0 
Testicles of a mature horse--- 
154.0 
221.0 
12.0 
55.0 
Egg yolks.--- 
2.5 
100.0 
1.5 
67.0 
Cod liver chum___ 
44.0 
173.0 
4.0 
92.0 
ANIMAL SUBSTANCES 
The foregoing observations and results 
on the occurrence of copper, manganese, 
and zinc in the foliage and seeds of im¬ 
portant agricultural plants suggested 
further investigations on their occur¬ 
rence in the tissues and fluids of domes¬ 
tic animals. The method of procedure 
used for all animal substances was 
substantially the same as the following, 
used for lean meat of an ox. A sample 
of lean meat from a freshly slaughtered 
mature normal ox was obtained, run 
through a meat chopper, and dried at 
100° C. One hundred grams of the 
moisture-free lean meat was heated 
gently in a clean quartz dish until no 
further volatile matter was given off. 
The carbonized matter was then 
digested with hot 20 per cent hydro¬ 
chloric acid and ground fine in a porce¬ 
lain mortar, transferred to a Buchner 
funnel, filtered and washed with hot 
water. The remaining residue of car¬ 
bonized matter was returned to a quartz 
dish and further ashed at a temperature 
below redness in a muffle furnace. 
This method of alternate ashing and 
extraction with acid and water was 
repeated until all the carbon was con¬ 
sumed and the mineral matter con¬ 
tained in the meat was in solution. 
The solution was made to a definite 
volume and aliquots taken for the esti¬ 
mation of the different elements re¬ 
ported in Table II 
DISCUSSION OF RESULTS 
From the results contained in this 
preliminary report it is evident that 
small amounts of copper, manganese, 
zinc, nickel, and cobalt are widely di¬ 
stributed in soils and plants. Each of 
these elements has been found in larger 
amounts than was anticipated in sam¬ 
ples of soil from a few of the larger 
geological formations in Kentucky. 
Examination of plants grown under 
natural conditions in the soil have re¬ 
vealed the presence of copper, manga¬ 
nese, and zinc in every case and in 
larger amounts than were anticipated. 
Nickel and cobalt occur in some of 
these plants in sufficient amounts to 
permit quantitative determination of 
these elements when not more than a 
kilogram of the dry plant material is 
ashed and these elements are carefully 
sought, using standard methods of 
chemical analysis. 
The fact that the liver of a young calf 
contained so much copper is both inter¬ 
esting and significant. Since the calf 
was only a week old it must have ob¬ 
tained all this copper from the mother 
cow. The calf was apparently normal 
in every respect at the time it was 
slaughtered. The fact that the calf ab¬ 
sorbed the amount of copper that it 
contained from the mother cow raises 
the question as to the effect on the 
offspring if the food of the mother cow 
