95 



TABLE I 



INFLUENCE OF NITROGEN MUSTARDS ON 

 CITRATE ACCUMULATION IN SPLEEN. THYMUS, AND LIVER 



OF IRRADIATED RATS 



Mg. /kg. of Ethyl 



Bis (p-chloroethylamine) Liver Spleen Thymus 



{'[ig. citric acid/g. fresh tissue) 



Control 64 1425 1045 



2.5 729 744 710 



POTTER: May I ask a question about the mechanics of an experiment 

 like that? When you do that, obviously you do not take all the rats at once and 

 inject them . 



DUBOIS: We usually injected one dose and killed groups of 4 animals 

 each day. All animals were not necessarily injected at one time. 



POTTER: But on any given day would you give them all the same dose? 



DUBOIS: Yes. 



POTTER: You would tend to give them one dose and then the next day 

 give them the next dose? 



DUBOIS: Yes. 



POTTER: No, I just mean in the statistical operation of the experi- 

 ment would you randomize your dosage in each case or not? 



DUBOIS: No. However, the doses given on successive days were not 

 always the next highest doses used in the study. The dose was either raised or 

 decreased on successive days depending on the outcome of the previous experi- 

 ment. The doses actually were randomized in this respect but this was not done 

 purposely. 



SHERMAN: Did you run controls each day? 



DUBOIS: Not each day. There was no reason to do so, because they 

 were always the same. Controls were run at intervals, say, of 2 weeks. I 

 don't think I got the point of Dr. Potter's question. 



POTTER: I am just raising the question of how many days the rats in 

 the bottom row had been on a given diet in comparison with the rats in the top 

 row. 



DUBOIS: They were all on the same diet for the same period of time 

 throughout the study. All animals weighed close to 225 g. and were the same age. 



