1890.] A Bacteria-killing Globulin. 93 



and in which the friction is reduced to a minimum, the mercury 

 column appears to acquire a certain momentum, so that the state- 

 ment in (3) no longer applies, and the instrument is not dead beat 

 in its action. It may, however, be made so by the introduction of a 

 sufficiently large resistance. 



There is also another form of overshooting, due to the elasticity of 

 the meniscus itself, the effect of which upon the curve is distinct, 

 and different. Both these forms of error are rare. 



(c.) Variations of Resistance during an Excursion. The principal 

 seat of the internal resistance of the capillary electrometer being the 

 slender column of dilute acid in the tube, the length of which varies 

 with the movement of the meniscus, it is evident that the total re- 

 sistance must vary during an excursion. The effect of this variation 

 of resistance may be detected in excursions of considerable extent, 

 and the amount of it measured. I have found that the error due to 

 this cause is seldom more in practice than one per cent,. The method 

 of applying these corrections, together with a description of the ap- 

 paratus employed, and a discussion of the points of theory involved, 

 I hope to publish at no distant date. 



The investigations of which the results are given above were 

 made in the Physiological Laboratory, Oxford, the resources of 

 which were placed at my disposal for the purpose by Professor 

 Burdon Sanderson. 



V. "A Bacteria-killing Globulin." By E. H. HANKIN, B.A., 

 St. John's College, Cambridge, Junior George Henry 

 Lewes Student. Communicated by Professor ROY, F.R.S. 

 (From the Pathological Laboratory, Cambridge.) Received 

 May 21, 1890. 



The results described in the present paper were arrived at by the 

 author while trying to discover the nature of the substance to which 

 the bacteria- killing powers of the blood serum were due.* 



The results obtained by Nuttall,f Buchner.J and Nissen have 

 shown that the blood serum, independently of any cellular elements, 

 has a certain power of killing bacteria. The method used by these 



* My work was aided by grants from the British Medical Association and from 

 the John Lucas Walker Fund. 



t " Experiments iiber die bakterienfeindlichen Einflusse des thierischen Korpers," 

 ' ZeitBchrift fur Hygiene,' vol. 4, 1888, p. 353. 



J " Ueber die bakterientodtende Wirkung des zellenfreien Blutserums," ' Central- 

 blatt fur Bakteriologie und Parasitenkunde,' vol. 5, p. 817, and yol. 6, p. 1, 1889. 



" Zur Kenntniss der baktcrienvernichtenden Eigenschaft des Blutes," ' Zeit- 

 schrift fur Hygiene,' vol. 6, 1889, p. 487. 



