The President's Address. Bij (I . S. Woodhead. 115 



It is sometimes cast up as a reproach against the surgeon and 

 physician that with all their microscopic examination of tumours 

 they have, as yet, been unable to find the cause or to explain the 

 origin of tumours. It must be remembered, however, that specific 

 etiology is, after all, but of recent growth, and although the 

 demonstration of the specific causes of a few diseases is still 

 awanting, we have still been able, even in those in which we 

 have failed to do this, to give guidance to the surgeon or physician 

 as regards the prognosis of his case, to help him in carrying out 

 treatment, and in many cases to relieve the suffering, both physical 

 and mental, of the patient. Before the days of the Microscope 

 the surgeon had little to guide him as to the probable course of 

 the various tumours that he met with. He knew that they could 

 be divided into benign and malignant, but he had few data on 

 which to determine to which class a particular tumour might belong. 

 With the advent of the Microscope all this was change* 1. Certain 

 tumours, although growing independently, were found when 

 examined histologically to depart little from the structure charac- 

 terizing normal tissues, and did not give rise to any secondary 

 growths ; these proved to be benign, and, except mechanically, 

 interfered little with the health of the patient. Other tumours 

 were found to depart somewhat widely from normal adult tissues 

 in arrangement, in their structure, rate of growth, and degree of 

 development. These often gave rise to secondary growths at a 

 distance, and so invaded and interfered with the tissues of the 

 vital organs of the body that they came to be looked upon 

 as malignant, in that the patient succumbed, sometimes very 

 rapidly, in consequence of this invasion. A microscopic examina- 

 tion of all tumours is now carried on as a matter of routine by 

 most surgeons at the time of operation, and the morbid histologist, 

 by gradual improvement of methods, has succeeded in showing 

 how these tumours spread, and even in marking the points to 

 which the tumour has advanced. He has enabled the surgeon to 

 become gradually more and more confident in effecting the com- 

 plete removal of these tumours, and so prolonging, sometimes to 

 the full span, the life of his patient. Again, dealing with a benign 

 tumour, a microscopical examination enables him to assure his 

 patient that it will not return, whilst, even in the case of malignant 

 tumours, he is able to give some indication as to whether he has 

 removed the whole of the ramifications of the tumour mass. 

 Thus, though the microscopist has not been able to demonstrate 

 the causes of tumour growth, his work has not been entirely in 

 vain. 



As one whose main interest in scientific work must necessarily 

 have a bias in the direction of pathology, I might descant for 

 hours on this aspect of the value of the Microscope in medicine, 

 but I realize that, except generally, it can have but little attrac- 



