142 Messrs. Browning and Gulbransen. Effect on Blood of 



Nuttall first drew attention, had contributed in a considerable measure to 

 the results obtained ; but it is to be noted that in all cases the controls, 

 consisting of fresh serum obtained immediately before the injection, yielded 

 after inoculation abundant growths of both organisms employed. Thus there 

 is evidence in our experiments that the natural bactericidal property of the 

 serum was not a decisive factor in producing the antiseptic effect. Staphylo- 

 coccus is not killed by serum, as Wright and Windsor pointed out in the case 

 of the human subject. In the case of B. coli, serum from the rabbit causes a 

 phase of bactericidal action, which is frequently succeeded by multiplication 

 (Chick) ; this latter phase of multiplication was of constant occurrence in our 

 investigations. 



In order to demonstrate further that the bactericidal effect following the 

 injection of diamino-acridine sulphate was independent of properties of the 

 fresh serum, experiments were also carried out with heated serum. 



Exanrvple. — Eabbit (weight, 1510 grm.). : 0"09 grm. diamino-acridine sul- 

 phate, dissolved in 20 c.c. of 0'85-per-cent. NaCl solution, injected into the 

 auricular vein in the course of five minutes (dose = 0'06 grm. per kilogramme 

 of body weight). Specimens of serum (a) fresh and (&) after heating for 

 one hour at 56° C. — taken (A) before, (B) 17 minutes after, the injection — 

 were inoculated with Staphylococcus aureus and £. coli as described above. 



The results after incubation for 72 hours at 37° C. were as follows : — 



Inoculation with Staph, aureus. 



Serum. 



A (before injection) 

 undiluted 



B (after injection) 

 undiluted 



B 75 per cent. 

 + 



A 25 per cent. 



B 25 per cent. 

 + 



A 75 per cent. 



Fresli 



Heated one hour 

 at 56° C. 



Abundant growth 

 (turbid) 



Abundant growth 

 (turbid) 



No gi'owth* 

 (clear) 



No growth* 

 (clear) 



No growth* 

 (clear) 



No growth* 

 (clear) 



Grrowth 

 (turbid) 



Growth 

 (turbid) 



Inoculation with S. coli. 



Serum. 



A undiluted 



B undiluted 



B 75 per cent. 

 + 



A 25 per cent. 



B 25 per cent. 

 + 



A 75 per cent. 



Fresh 



Heated one hour 

 at 56° C. 



Abundant growthf 

 (turbid) 



Abundant growthf 

 (turbid) 



No gi-owth* 

 (clear) 



No growth* 

 (clear) 



No growth 

 (clear) 



No growth 

 (clear) 



No growth* 

 (clear) 



Grrowth 



* Subcultures on agar yielded scanty colonies. 



t With B. coli growth in the heated serum was abundant after 24 hours ; in the unheated 

 serum the growth was scanty after 24 hours, but became marked later ; tliis may be taken as 

 evidence of the natural inhibitory effect of fresh serum. 



