78 BACTERIOLOGY OF THE EYE 



such on Staph. aureus and Bac. subtilis, and more freely the less the 

 number and virulence of the Bacteria in question. On the Micrococcus 

 prodigiosus the tears had no influence. Marthen 1 demonstrated some 

 action on Staphylococci, and investigated at the same time the results 

 on some saprophytes (Micrococci and Sarcime) ; a certain diminution 

 in their number occurred under the influence of the tears. Bach 

 obtained positive bactericidal results with Staphylococcus aureus and 

 B. typliosus, though not invariably. A similar result was obtained 

 with saline solution of the same concentration, 2 dialysed blood-serum, 

 and distilled water. According to Bach, heating the tears has no 

 effect on this action, which he terms bactericidal ; it cannot therefore 

 be due to the serum albumin. The Kieler water bacillus is not 

 affected. 



Valude was the first to announce the view that the lacrymal sac was 

 not susceptible to infection by tubercle bacilli, because of the bac- 

 tericidal action of the tears. Gourfein 3 showed, however, that the 

 bacterial emulsion injected by Valude had simply flowed through the 

 tear passages, and had not settled in them. When he introduced a 

 pure culture into the sac and allowed it to remain there, tuberculosis 

 regularly supervened. Valude 4 then conducted further experiments 

 with a retention fluid collected under the lids which had been stitched 

 together, and concluded that the tears are not merel} T a bad 

 nutritive medium for the tubercle bacilli, but that they produce a 

 lowering of virulence. With Staphylococci there certainly was no 

 bactericidal action. (The whole experiment still leaves in doubt the 

 question whether the fluid used really was similar to the tears.) 



Ahlstrom 5 could demonstrate no bactericidal action in sterile tears obtained from 

 a fistula of the lacrymal gland ; in the majority of the experiments the Staphy- 

 lococci increased. With tears from a patient with conjunctivitis he obtained a slight 

 diminution, which he attributed to the lower alkalinity. Bach, after repeating his 

 experiments with alkaline saline, protested against such a conclusion. 6 



In a later communication Bach 7 stated his views more precisely : the action (of 

 the tears) resembled that of saline or water, and was far less important than the 

 mechanical effect. 



1 ' Experimental Research on Antisepsis in Eye Operations and the Bacteriology of the 

 Conjunctival Sac' (Beit. z. Aug., 1893, xii., S. 1). 



a Francke argues against any bactericidal action of normal saline on the Staph. pyog. aur. 

 Bach, on the other hand, insists that when the aureus culture is thus diluted down it will 

 die in twenty-four to forty-eight hours. The name ' bactericide ' has been given up by 

 Bach. , 



3 ' Etude Experimentale sur la Tuberculose des Voies Lacrimales ' (Ann. d'Ocul., 1899, 

 cxxi. 351). 



4 ' Action Bactericide des Larmes ' (Ann. d'Ocul., cxxii. 168, and IX. Inter. Congr., 

 Utrecht). 



5 Zent.f.Aug., 1895, S. 193. 



6 A.f. A. 1898, xxxiii., S. 102. 7 Z.f. A., 1903, Bd. xi., S. 1. 



