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10, 1923] 
» at all i jin the physiological equipment of the men who 
studied medicine at that time and are now in the full 
tide of practice. Even the professional physiologist 
finds it difficult to keep himself abreast of the course of 
discovery in his own subject. It would seem, therefore, 
almost impossible to expect a man in a busy practice to 
appreciate what recent physiology has done andsis doing 
for his science and for his craft. Many men, and those 
‘not the least successful, do not attempt the task, and 
trust to their craftsmanship and their powers of naming 
_ a diseased condition, that is, of placing it in a category 
familiar to them which they therefore believe they 
understand, and to their experience in treating such 
_ cases without, at any rate, harming the patient. 
At the present time the condition is improved by the 
establishment of clinical units, of which the heads have 
time and opportunity, not only to advance their own 
subject, but also to keep abreast of the more important 
researches in the collateral sciences, so that they may 
serve to some extent as interpreters of the latter to their 
professional brethren. But even for the practitioner 
who is not so fortunately situated the task is not so 
- impossible, if his training in physiology has been of the 
right character and has fallen on favourable soil. In 
the physiological training of the student it is not 
collections of facts or strings of arguments which are of 
supreme importance, but the method by which these 
_ facts are attained and the attitude of mind of the 
investigator. If he can carry this method and this 
attitude of mind into the wards, every case becomes for 
him a physiological experiment. Diagnosis is not the 
application of some appropriate label, but an under- 
standing of what is happening in the body and how the 
disorder of any given function has come into existence. 
_ The whole of his practice becomes a research, and with 
one problem after another crying out for solution his 
attention and his curiosity are kept awake for any light 
which may be thrown by physiology or other science on 
the questions with which he has to deal. The true 
scientific physician must remain a physiologist during 
his whole life. 
In the work under review Dr. Sainsbury shows that 
he has not forgotten the lessons in physiological method 
and thinking that he learned with Sidney Ringer. 
Taking as his text the action of the heart and the 
modifications that this may undergo in disease, he 
endeavours from his pathological and clinical experi- 
ence to reconstruct the conditions in the living organism 
and, as he says, “ to visualise the organs and tissues 
dynamically.” He shows that in every case the test 
of structure must be the functional adequacy of the 
tissue. Given a case of heart disease the important 
thing is not an intimate analysis of the heart sounds 
and their modifications, but the knowledge of what the 
NO. 2784, VOL. 111] 
NATURE 

315 
heart can do, and what are its powers as a pump, 2.e. in 
maintaining the circulation of the blood. 
In the first chapter, on the anatomical relations of the 
heart, the author gives an interesting series of measure- 
ments of the relative weights of the different parts of the 
heart, and shows that the muscular tissue surrounding 
each cavity is roughly proportional to the work that the 
cavity has to do in the maintenance of the circulation 
of the blood. Thus the muscular tissue of the auricles 
is roughly only one-tenth of that of the two ventricles, 
while the muscular tissue of the right ventricle as com- 
pared with that of the left ventricle is a little less than 
one-third of the latter (t-—2:5). In this case there 
would seem to be a discrepancy between the mass of 
the muscle and the actual work done by each cavity. 
It is probable that the work of the left heart is five or 
six times as great as that of the right ventricle. The 
smaller difference in the muscular tissue may be due 
to the greater mechanical disadvantage attendant on 
the arrangement of the muscular fibres of the right 
ventricle. 
When we consider the enormous strain that may be 
thrown upon the walls of the left ventricle during 
exercise it is astonishing to find that one part of its 
wall, namely, that of the extreme apex, is only a few 
millimetres thick. Dr. Sainsbury points out that the 
heart would tend to rupture at this point if it had to 
sustain the full pressure of the blood during the ventri- 
cular systole. He suggests that at the very beginning 
of systole the blood is squeezed out from the apex by 
the preliminary contraction of the vortical fibres at this 
spot. As a matter of fact, Lewis has shown that the 
vortex of the left ventricle is one of the places where the 
wave of negativity preceding contraction appears 
earliest, though the time is short which elapses between 
the appearance of the wave at the apex of the ventricle 
and that at other parts of the two ventricles. It must 
be owned that electrical measurements give no support 
to the further hypothesis of the author, namely, that 
the circular band of fibres surrounding the left ventricle 
must contract later than the spiral fibres. 
Attention is directed to a fact which often escapes 
notice, namely, the large size of the aorta and big veins 
as compared with the heart. Here we have a pump 
putting out about 4 oz. of blood at each stroke into a 
vessel 1} inches in diameter, and the big veins entering 
the heart have a total cross-section even larger. We 
should be almost justified in speaking, therefore, of an 
arterial sac and a venous sac, each serving as a reservoir 
of blood to supply the arterial system and the heart 
respectively. 
It is always difficult to judge of the relative value of 
results obtained by different methods in a science with 
which one is not in daily contact. In Dr. Sainsbury’s 
