PRESIDENTIAL ADDRESS. 653 
direct appeal to the biological mind. Its results are expressed in more general 
terms and the bearing of its applications are perhaps more obvious, especially 
at the present moment. This fact increases the danger of a further neglect in 
biology of the organic structural side of chemistry, upon which, nevertheless, 
the whole modern science of intermediary metabolism depends. On the other 
hand, I think one may say that there are only a few among the present leaders 
of chemical thought in our midst who have set themselves to appraise with 
sympathy the drift of biological processes or the nature of the problems that 
biologists have before them. Anyone wishing to see the number of biochemical 
workers increased might therefore with equal justice appeal to the teachers of 
biology or to the teachers of chemistry for greater sympathy with the border- 
land. It is a moot point indeed as to which is the better side for that borderland 
to recruit its workers from. 
But on the whole it is easier for the intelligent adult mind to grasp new 
problems than to learn a new technique. It is better that youth should be spent 
in acquiring the latter. That is why, though I admit that it would have been 
more obviously to the point if made some ten years ago, I feel justified in 
repeating to-day the appeal of Liebig to the leading chemists of this country, in 
the hope that they may see their way to direct the steps of more of their able 
students into the path of Biochemistry. I have been specially tempted to do 
this, rather than to speak upon some of many subjects which would have 
interested this section more, for a very practical reason. I have been in a 
position to review the current demand of various institutions, home and colonial, 
for the services of trained biochemists, and can say, I think with authority, that 
the demand will rapidly prove to be in excess of the supply. It will be a pity 
if the generation of trained chemists now growing up in this country should not 
share in the restoration of this balance. You certainly have the right to tell me 
that I ought, under the circumstances, to be addressing another section; but it 
may be long before any member of my cloth will have the opportunity of appeal- 
ing to that section from the position of advantage that I occupy here. I believe 
you will forgive the particular trajectory of my remarks, because I am sure 
you will sympathise with their aim. Moreover, I have some hope that the 
considerations upon which I shall chiefly base my appeal will have some interest 
for members of this section as well as for the chemist. My main thesis will be 
that in the study of the intermediate processes of metabolism we have to deal, 
not with complex substances which elude ordinary chemical methods, but with 
simple substances undergoing comprehensible reactions. By simple substances 1 
mean such as are of easily ascertainable structure and of a molecular weight 
within a range to which the organic chemist is well accustomed. JI intend also 
to emphasise the fact that it is not alone with the separation and identification 
of products from the animal that our present studies deal; but with their 
reactions in the body; with the dynamic side of biochemical phenomena. 
I have made it my business during the last year or two to learn, by means of 
indirect and most diplomatic inquiries, the views held by a number of our lead- 
ing organic chemists with respect to the claims of animal chemistry. I do not 
find any more the rather pitying patronage for an inferior discipline, and cer- 
tainly not that actual antagonism, which fretted my own youth; but I do find 
still very widely spread a distrust of the present methods of the Biochemist, a 
belief that much of the work done by him is amateurish and inexact. What is 
much more important, and what one should be much more concerned to deny 
(though but a very small modicum of truth is, or ever was, in the above indict- 
ment), is the view that such faults are due to something inherent in the subject. 
My desire is to point out that continuous progress, yielding facts which, by 
whomsoever appraised, belong to exact science, has gone on in the domain of 
animal chemistry from the days of Liebig until now, and that if this progress 
was till recently slow, it was, in the main, due to a continuance of the circum- 
stance which so troubled Liebig himself—the shortage of workers. 
But we must also remember that the small band of investigators who con- 
cerned themselves with the chemistry of the animal in the latter half of the 
nineteenth century suffered very obviously from the fact that the channels in 
which chemistry as a whole was fated to progress left high and dry certain 
regions of the utmost importance to their subject. In three regions particularly 
the needs of Biochemistry were insistent. The colloid state of matter dominates 
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