350 SEQUENCE OF EVENTS IN LOCAL LESIONS 



benefit from vaccine injections which raise the index, and more 

 especially in cases in which there is a free drain for the toxins 

 ulcers, open abscesses, sinuses, etc., or in those in which there is 

 no dead material (slough or caseous matter), and the blood is 

 brought into close contact with the bacteria. Small isolated 

 tubercles in the iris often yield rapidly to tuberculin injections* 

 whereas large caseous glands are most refractory. 1 Chronicity is 

 also an important factor : a long-standing thick-walled abscess is 

 less amenable to treatment than a small freshly formed boil. 



In order to aid this flow of plasma or lymph laden with pro- 

 tective substances through the lesion, Wright has suggested the 

 exhibition of substances such as citric acid or leech extract, which 

 have the power of diminishing the coagulability of the blood. In 

 certain cases the beneficial effects of these remedies may be most 

 striking. And the local use of hot fomentations, etc., which dilate 

 the vessels, has a similar effect ; in addition to which they probably 

 aid phagocytosis by raising the temperature of the part. 



Next as regards the other pre-existing defensive substances of 

 the plasma the bacteriolysins. In the case of the staphylococci 

 there is no reason to think that they are of any importance, since 

 most authorities hold that there is no proof that serum has any 

 bactericidal action on these organisms under any circumstances. 2 

 And when the blood does normally contain the amboceptor- 

 complement apparatus, the establishment of the lesion sufficiently 

 demonstrates the insufficiency of this apparatus for defence. 



At a later stage, supposing the pre-existing defences opsonin 

 and leucocytes, etc. fail to bring about cure, a second series of 

 factors come into action. These are the antibodies, the chief 

 being antitoxin, amboceptor, and thermostable opsonin, the latter 

 being possibly either agglutinin or amboceptor, as we have seen 

 already. These usually take about a week to be produced, and 

 may be looked upon as the second line of defence. 



As regards their place of production, this may be remote or 

 local. The sites of general production of the antibodies have 



1 In saying this I do not wish to imply that the cure in these cases, and after 

 the use of vaccines in general, is brought about solely by an increase in the 

 opsonins of the blood, 



2 I must point out, however, that in old staphylococcic abscesses it is 

 common to find cocci which have lost their power of retaining Gram's stain, 

 an invariable proof (where applicable) of the early stages of bacteriolysis. 

 This is probably due to the action of the peptic enzyme formed by the 

 leucocytes. 



