200 Studies on the Relation of Minerals to Live Weight
On the other hand Mitchell and McClure (loc. cit.) remark (p. 53, foot note)
that ' such heterogenous data cannot be analysed statistically in a satisfac-
tory way by the simple methods used by Sherman '. Nevertheless his values
appear to have been in some cases tacitly accepted for application not only
for human adults but also for other animals. Thus in the text and tables
given by Mitchell and McClure (loc. cit.) the requirement seems to have been
assessed on the basis of Sherman's method of lime and phosphorus require-
ment related to the corresponding amount of protein requirement (vide equa-
tion p. 62).
The other notable work viz. that of Leitch refers to a linear relation with
output and intake. She first analysed the total available experimental data
for women but rejected a large part because as she states, ' the calcium intake
has been planned as so much per kg. of body weight and hence the requirement
deduced by Sherman's method would be closely correlated with body weight'.
She divided the remaining data under three sets of body weights viz. 50—55,
55—60 and 60—65 kilos. According to her statement the average positive
or negative balances ' show no correlation with body weight'.
It is not clear, however, from her paper if the data on live weights were
statistically analysed in relation to output and intake. She grouped her
final data under a sliding range of intakes and averaged them within each range.
In this way she obtained 13 averages for negative balances (ranging from
an average intake of 0.080 to 0.650 gm. Ca), and 11 averages for positive
balances (ranging from 0.196 gm. to 0.742 gm. Ca). Using the corresponding
output as ordinate she drew two regression lines against these intakes and the
point of equidistance from these two lines was assumed by her as the
index of requirement, the body weight apparently exercising no influence.
This she called as the ' true maintenance requirement for women ', and
according to her ' there seems to be no reason why this standard should not
be used for adults generally '.
In the work conducted in Bengal it was considered that a more appropriate
course would be to approach the problem in such a way that all relevant data
might admit of a statistical examination. The intakes and outputs were used
from experiments conducted under the direct control of the Animal Nutrition
Section in Bengal, started under the grant of the Imperial Council of Agricul-
tural Research. Besides, the data were only from those metabolic tests in
which the main source of lime was from the same variety of rice straw viz.
high land aus. The experiments were conducted at two centres viz. Krish-
nagar and Dacca. In the Krishnagar experiments eight adult bullocks were
by rotation put under ½ lb., 1 lb., 2 lb. and 3 lb. mustard cake as concentrate
and aus straw ad lib as roughage. The experiment lasted for a period of about
six months and the metabolic and digestion tests in each cycle were carried
out for a period of ten consecutive nights and days. In the case of 3 lb.
combination there was great disinclination on the part of the majority of ani-
mals to eat the cake in entirety. Only two animals behaved satisfactorily,
consequently these two were taken while the others were rejected. One full
set of trials embracing eight individual tests had to be rejected on account
of the administration of aman variety of rice straw which is grown in low
inundated areas. In addition to these, four more animals (in all twelve) were
rejected for sickness and other reasons such as disinclination for eating etc.