22 Proceedings of the Royal Physical Society. 
as a result of the intense reaction—the tissues apparently 
dying before the eyes of the observer. In those cases where 
the lupus is sharply defined, the central portion correspond- 
ing to the tubercular granulation tissue becomes swollen and 
brownish, and eventually dies. Surrounding this centre is a 
whitish rim, almost a centimetre wide, the exact nature of 
which is not evident, though we may expect to find that it 
consists of an odematous connective-tissue area; whilst outside 
again is a broad band of bright red inflammatory tissue (corre- 
sponding to the old hyperzemic zone), in which there appears 
to be, from all accounts as yet received, an attempt made by 
the healthy tissues to still further localise the mischief. 
Should a similar series of changes take place in the tuber- 
cular areas of bones and joints, the question of operation— 
after the injection of the lymph has done its work—will of 
course be settled, and the same will apply to glands or other 
tubercular tissues that are accessible to the surgeon’s knife. 
Indeed, with the present facilities that we have for carrying 
on cranial and abdominal surgical operations, we can quite 
see that, in the event of Koch’s observations being confirmed, 
there can be almost no limit to the application of surgical 
interference in such cases; for as it is pointed out by eminent 
surgeons, it will not be a very difficult matter to remove from 
the lung a localised mass of tubercle, or a series of masses, 
even in those cases when drainage of tuberculous cavities 
would be out of the question. | 
Before allowing ourselves to be carried away by too great 
enthusiasm concerning what is undoubtedly a marvellous 
discovery, we must, in addition to the facts mentioned above, 
bear in mind that Koch himself has insisted that the reason 
no tubercle bacilli can in many cases be demonstrated in 
caseous areas is, that as soon as the conditions have become 
somewhat unfavourable to the existence of the bacillus, 
spores are formed, and these remaining (although undemon- 
strable) in the caseous mass, may prove a fruitful source of 
infection for long periods after the bacilli themselves have 
disappeared. It is for this reason that the danger of removing 
tuberculous masses by scraping and cutting has hitherto been 
insisted upon. If this danger be present in the normal course 
