534 



Dr. W. Bulloch and Mr. G. T. Western. ' [Feb. 15, 



2. Normal human serum was mixed with an equal quantity of an emulsion 

 of Staphylococcias aureus in 085 per cent. NaCl solution. The mixture was 

 digested for 30' at 37° C. and then eentrifuged, a supernatant liquid "B" 

 being obtained. 



3. The fluid " A " was mixed with an equal quantity of an emulsion of 

 Staphylococcus aureus. The mixture was digested for 30' at 37° ,C. and a 

 deposit separated from a fluid " C " by the centrifuge. 



4. The fluid " B " was mixed with an equal quantity of an emulsion of 

 tubercle bacilli. The mixture was digested for 30' at 37° C, and a deposit 

 separated from a fluid " D " by the centrifuge. 



The opsonic content of the serum and of the fluids "A," "B," "C,"and 

 " D" was then determined both for Staphylococcias aureus and tubercle 

 bacillus in the usual way. the necessary controls being added. In the first 

 experiment the determinations made by each of us separately in a series of 

 different films are given under the designation B. and W., and the mean of, 

 these determinations. In the second experiment the result was obtained , by 

 one Of us (W.) alone. 



It will be seen that a considerable degree of specificity exists in so far that 

 staphylococci remove almost the whole of the opsonin for this microbe, while 

 the opsonic substance for tubercle bacilli is in large part left unaltered. In 

 almost all cases we have observed a slight diminution in the quantity of the 

 opsonin left behind. Thus while the contact of a serum with tubercle bacilli 

 lowered the opsonic content for this bacillus from 3"03 to 04, it also pro- 

 duced a slight lowering of the staphylococcus opsonin from 11*2 to 096. 

 Similarly, contact of a staphylococcus with serum reduced the staphylo- 

 coccus opsonin from 12-45 to - 34, and at the same time it lowered the 

 tubercular opsonin from 3 - 015 to 2*7. 



2. Experiment : — 



The opsonic content of the serum of a patient suffering from lupus was 

 repeatedly determined on tubercle and staphylococcus Suspensions. Two 

 inoculations of tuberculin and two of staphylococcic vaccine were injected, 

 and the influence of the inoculations is set forth in the following opsonic 

 curve, which shows that there is no correspondence in the quantities of 

 tuberculo-opsonins and staphylococcus opsonins when one or other of the 

 corresponding vaccines is inoculated (Case I). 



In a second experiment (Case II) opsonic determinations were made in a 

 similar case, with the exception that the patient was not only suffering from 

 lupus, but septic infection of the tuberculous lesions at the same time 

 (Curve 2). 



