\ 



140 Messrs. Browning and Gulbransen. Effect on Blood of 



CH 



CH 



H.N— . 



-NHo 



IS" 



/\ 

 CH., CI 



Diamino-methyl-acridinium 

 cliloride. 



Diamino-acridine 

 (base). 



We have investigated the question in the case of mice infected with 

 Tr. rJwdesiense* The mice were inoculated by subcutaneous injection of a 

 dilution of richly infected blood. After several days, when parasites were readily 

 found in their blood, a series of animals received varjdng doses of diamino- 

 methyl-acridinium chloride and diamino-acridine sulphate. The maximum 

 dose of the acridinium compound tolerated by infected animals (0'0003 grm.) 

 caused disappearance of the parasites from the blood for a number of days as 

 a ride, so that great protraction of the infection resulted. With diamino- 

 acridine sulphate, although a much larger dose was well tolerated 

 (O'OOlo grm.), there *\vas, as a result, only very slight protraction of the 

 infection as compared with the untreated controls. The latter invariably 

 died, although the number of trypanosomes in the blood, after increasing to 

 a maximum, frequently receded spontaneously, only to increase again prior 

 to death. Thus, although the infection with this strain of trypanosomes in 

 mice was by no means ideal for chemo-therapeutic observations, the fact of 

 the great superiority of the acridinium compound in this respect was clearly 

 apparent. 



The main experiment consisted in introducing diamino-acridine sulphate in 

 0'8o-per-cent. NaCl solution intravenously into rabbits, and then withdrawing 

 specimens of blood at intervals. The blood was allowed to coagulate, and the 

 serum was withdrawn under aseptic precautions, and was freed from cellular 

 elements by centrifugalising. Quantities of 1 c.c. each of unheated serum 

 were then inoculated with Ol c.c. of a 1 : 20,000 dilution of a 24-hour 

 peptone water culture of Staphylococcus aureits or B. coli, and these cultures 

 were incubated at 37° C for 48 hours or longer. By way of control, a 

 specimen of blood was taken before the injection, and was similarly 

 inoculated. The majority of the animals manifested no signs of illness 

 during or after the injections, and were alive and well many weeks later. 

 The following are characteristic examples : — 



Rahhit No. I (weight, 1950 grm.). — O'lo grm., dissolved in 45-5 c.c. of 

 0-85-per-eent. NaCl solution, injected into the auricular vein in the course 

 of 9-| minutes (dose = 0"066 grm. per kilogramme of body weight). 



* We are indebted to Prof. Warrinsrton Yorke for the strain. 



