Intravenous Injections of Diamino-Acridine Sulphate. 143 



Thus, it has been shown that in rabbits, a dose of diamino-acridine 

 sulphate, which is well tolerated when introduced directly in the blood 

 stream, is capable of rendering the blood serum antiseptic or of augmenting 

 greatly its bactericidal power, and that this property is still manifested 

 several hours after the injection. A great part of the substance rapidly 

 enters the muscles, which become of a distinct yellow tint, but this does not 

 affect the fact just stated. Accordingly, there appears to be here a very 

 promising indication as to the lines on which a chemo-therapeutic agent 

 applicable to cases of bacterial septicaemia is to be sought.* 



Diamino-acridine sulphate is absorbed from the alimentary tract, and, after 

 administration by this route or intravenously, the urine soon exhibits the 

 canary-yellow fluorescence, best seen on dilution, which is so characteristic 

 of weak solutions of the acridine compounds. There is also excretion of the 

 substance by the bile. Observations on the human subject treated by 



* We are indebted to Dr. H. H. Dale, F.R.S., for the blood-pressure record of an 

 experiment in wliich he injected 0'3 grm. of the diamino-acridine sulphate in a volume 

 of 100 c.c. intravenously into a monkey weighing 4'3 kgrm., under an anaesthetic. 

 Specimens of serum taken during and after the injection (see below), both fresh, and 

 also after heating for half an hour at 56' C, failed to yield growths after inoculation 

 with staphylococcus and B. coli. 



The results are as follows : — 



Time. 



Ansesthetic. 



Blood-pressure at 

 end of period. 



Total amount of substance 

 injected (1 : 300 solution) 

 in each period. 



Commencement of record 



17 minutes later 



16 „ „ 



18 .„ „ 



15 „ „ 



5 » 



13 „ „ 



21 „ „ 



A.C.E. 



Ether 



100 mm. Hg 

 90 „ „ 

 .75 „ „ 

 Eapid fall toT^•ards the 

 end of this period 

 to 45 mm. , and heart 

 irregularly inhibited 

 55 mm. Hg 



60 „ „ 



60 mm. Hg (heart 

 rather severely in- 

 hibited) 



60 mm. Hg (heart in- 

 hibition passed off:) 





 



22 c.c. run in intermittently. 

 40 c.c. run in continuously 



(at first 2 c.c. per minute, 



soon increased to 3 c.c. per 



minute) 

 (20 c.c. blood withdrawn 



from carotid) 







38 c.c. (20 c.c. blood with- 

 drawn from carotid) 



(20 c.c. blood withdrawn, 

 then animal bled com- 

 pletely) 



The conclusion from this .single experiment is that when an animal of similar 

 susceptibility receive.s an intravenoas injection under an an;t.sthetic, administration 

 at as great a rate as 0"0025 grm. per minute per kilogramme of body weight causes 

 some danger to the heart (under similar conditions this would mean that an average 

 man weighing 60 kgrm. should not receive an intravenou.s injection at a rate exceeding 

 0'1.5 grm. per minute or 50 c.c. of a 1 : 330 solution). There is, of course, considerable 

 likelihood that the an£e.sthetic tends to increase the susceptibility of the heart. 



