RECENT ADVANCES IN SCIENCE 573 



This third case can be explained only by supposing that the 

 nervous system has become unduly excitable, so that a small 

 effort on the part of the heart sets up a great effect. And we 

 can only explain the increase in nervous excitability by 

 supposing that toxins of disease are acting upon the nerves. 

 We thus reach the position that the presence of a toxin in the 

 body may so raise nervous excitability that a healthy heart, in 

 its normal responses to effort, sets up a symptom — pain — ^which 

 is identical with the pain occasioned by a diseased heart. 



We have thus found an earlier period of disease than that 

 which can be recognised by examination of organs. We have 

 also disentangled a law — that some of the symptoms of disease 

 are exaggerations of normal reflexes. Because the normal heart, 

 under great effort or strain, gives rise to the same kind of pain. 



Sir James Mackenzie and his co-workers have already found 

 that what is true of the symptom — pain — is true also of many 

 other symptoms ; for example, breathlessness and exhaustion. 

 Thus, a new position in regard to medical research is being taken 

 up, and the study of early symptoms entering upon a practical 

 stage. 



Some fascinating possibilities open before the mind. If, for 

 example, the poisons of disease act on various portions of the 

 nervous system and so disorganise the nervous control of organs, 

 it may well be that, in process of time, those organs will break 

 down from this reason alone. Thus, destruction of the lung in 

 tuberculosis may not be so much the cause of the disease as one 

 of its effects. The cause may be remote, in a general poisoning 

 of the system, and the local focus of trouble may arise owing 

 to this general poisoning. Thus a new world comes into view. 



We wrote last month of the third partner in disease — the 

 factor which prepares the soil for the seed. It will be seen that 

 the search for these third partners cannot leave out of account 

 the work at St. Andrews, which indeed offers a field for pioneer 

 endeavour of the most fascinating description. 



