Bacteriolytic Element found in Tissues and Secretions. 311 



Influence of Temperature, on the Velocity of Lysozymic Action. 



The lytic action takes place slowly in the ice chest and the velocity 

 increases up to 80° C. after which it becomes slower again, probably owing to 

 the destruction of some of the lysozyme. 



If lysozyme containing material, however, is left in contact with the 

 Micrococcus lysodeikticus for 24 hours the cocci are dissolved in the same 

 dilution of the lysozyme whether the reaction takes place at room tem- 

 perature, 37° C, or 50° C. 



Does the Lysozyme pass through Membranes or Filters ? 



1. Collodion. — One c.c. of a saline extract of sputum was placed in a 

 collodion sac and this was suspended in a tube containing a thick suspension 

 of M. lysodeikticus and incubated for 6 hours. No lysis of the cocci took place. 

 The sac was then punctured and the contents allowed to mix with the 

 bacteria when complete lysis occurred within 2 minutes, showing that the 

 sputum extract contained lysozyme, which, however, had been unable to 

 pass through a collodion membrane. 



2. Porcelain Filter. — Fifty c.c. of a 1 in 1,000 dilution of tears were passed 

 through a Berkfeld filter and it was found that the filtrate was devoid of 

 lysozyme action. As it might have been possible that some inhibitory 

 substance (e.g., acid or alkali) had been absorbed from the filter and passed 

 into the filtrate a small quantity of the unfiltered tears was added to the 

 tubes containing the filtrate and the cocci when lysis promptly occurred 

 showing that the lysozyme had actually been retained on the filter and that 

 the absence of lysis when the filtrate and cocci were mixed, was not due to 

 the presence of any inhibitory substance. 



It was impossible to obtain human secretions, rich in lysozyme, in 

 sufficient quantity to filter them in a strong concentration through the 

 porcelain filters available. Egg white, however, which is very rich in 

 lysozyme, was used for this purpose in a dilution of 1 in 10 in normal saline 

 solution. The filtrate was collected in separate portions of about 1 c.c, and 

 each portion was tested for the presence of lysozyme. The first 19 c.c. 

 which passed through the filter had no lytic action on M. lysodeikticus but 

 after that the lysozyme passed through and in the 30th c.c. the strength of 

 the filtrate was practically the same as that of the unfiltered material. 



These experiments show that a porcelain filter is capable of absorbing a 

 considerable quantity of lysozyme, but when that has been absorbed the 

 filter offers no barrier to the passage of this substance. We shall see that 

 the same thing happens with filters of cotton wool and filter paper. 



