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Mueellanea 
undoubtedly starts with the well-known coiiclu.siou that a Calorie in the food absorbed in a 
mixed diet from whatever source, protein, fat or carbohydrate is of equal dynamic value. 
Previous work amply justifies this. 
She was not foolish enough to attempt to draw any conclusion from her investigations as 
to the relative value of animal and vegetal:)le food in the diets on the physical development 
of the indi\'iduals. 
Professor Pearson seems entii-ely unable to grasp the fundamental fact that the physical 
develoimient of the individual depends largely upon his past conditions of life. To co-relate 
it with the special constituents of the food which he habitually eats will require not only an 
enormous series of studies, but a full investigation of the character of the various food stuffs 
and of the mode of cooking. 
These points I tried to explain to him when I wi'ote to him in summer. He did not 
write to me as, in his criticism, he says he did. Miss Lindsay forwarded to me a letter 
from him to her, and I wrote a reply to Professor Pearson which he did not acknowledge. 
In conclusion I would say that before he expects his criticism of a physiological problem 
to be taken seriously, he had better make some attempt to understand the nature of the 
problem. Certainly it is not my intention to waste time in replying further to his criticism 
unless in the future it is more pertinent than is his present contribution. 
II. The Statistical Study of Dietaries. A Rejoinder. 
By KARL PEARSON, F.R.S. 
I PUBLISH Professor Noel Paton's repl}- because it is veiy typical of the type of difficulty 
wliich we meet with at present, when we assert that what is really statistical work must be 
undertaken only by the adequately trained statistician and that when it is not, then the 
investigation cannot be considered as falling into the field of science. 
Professor Paton states that the following question gi\'en on p. 4 of the Report formulated its 
object : " Do the working classes of this city get such a diet as will enable them to develop into 
strong, healthy, energetic men, and as men, will enable them to do a strenuous day's work ; or 
are the conditions of the labouring classes such that a suitable diet is not obtainable?"... 
Now Professor Paton either assumes that the sample taken of the diet of the individual 
family was their customary diet, or he does not. If he does, then the question : Was the diet 
such as would enable the working classes "to develop into strong, healthy, energetic men"? 
has meaning. If he does not, not only is it idle, but the section dealing with the physique of 
the children on the basis of a sample diet taken as a rule /or a v)eek (occasionally for a fortnight), 
is beside the point. 
But anyhow, I ask how he can possibly ascertain how the working classes will " develop into 
strong, healthy, energetic men," if he does not take an adequate anthropometi'ic survey of the 
families subjected to the dietaries recorded ? He says that it is accepted and proved that " If 
a family diet... gives a yield of energy of less than 3500 calories per man per day it is insufficient 
for active work ; and if less than 3000, it is quite inadequate for the proper maintenance of 
growth and normal activity." He further assumes with Miss Lindsay that calories from animal 
and vegetable foods have equal "dynamic value." I assert that neither of these conclusions, 
