UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 915 



Contribution from the Bureau of Chemistry 

 CARL L. ALSBERG, Chief 



Washington, D. C. 



November 12, 1920 



TOXICITY OF BARIUM CARBONATE TO RATS. 



By Erich W. Schwartze, Junior Pharmacologist, Pharmacological Laboratory. 



CONTENTS. 



Purpose of investigation 1 



Previous investigations 1 



Experimental procedure 3 



Results of experimental work 4 



Minimum efficient concentration of barium 



carbonate 6 



Page. 

 Results of experimental work on other barium 



com pounds 9 



Toxicity of barium carbonate to animals 



other than rats 9 



Conclusions ." 9 



Bibliography 10 



PURPOSE OF INVESTIGATION. 



A series of experiments on the toxicity of various substances to 

 rats and their suitability for poisoning these animals was undertaken, 

 in 1918, at the request of the Bureau of Biological Survey of the 

 United States Department of Agriculture, for the purpose of obtain- 

 ing toxicological data for use in connection with the rat-extermina- 

 tion work in the zone of occupation of the American Expeditionary 

 Forces. Although this incentive ceased with the signing of the armis- 

 tice, the studies have been continued because of their importance to 

 agricultural economics as well as to the public health, 



PREVIOUS INVESTIGATIONS. 



The literature contains no references to work dealing with the 

 toxicity of barium carbonate to rats, in spite of the fact that many 

 articles give directions for its use as a rat poison and discuss its tox- 

 icity to other animals. The earliest communication which is of in- 

 terest here is one by Crampe (5), 1 who recommended 20 per cent 

 barium carbonate in bait for poisoning field mice. Lantz's (9) ba- 

 rium carbonate formula also calls for 20 per cent of this substance. 

 Recently White (20) has reported good results from poisoning Mus 

 ratlus by the use of 25 per cent of barium carbonate. This concen- 

 tration, however, was ultimately diluted, as water was added to the 

 barium, carbonate bait mixture. White set out individual baits 

 containing 3 grains (200 mg.) of barium carbonate. If entirely con- 



1 The figures in parentheses refer to the bibliography at the end of this bulletin. 

 10939°— 20-Bull. 915 



