TOXICITY OF BARIUM CARBONATE TO RATS. 



From 630 to 750 mg. per kilo was found to be the least amount 

 which could be considered efficient. On increasing the amount 

 administered, however, there were still a few survivals, although the 

 increased potency of the larger doses was clearly indicated by the 

 relative increase of fatalities occurring within the first 16 hours. 

 The occasional survival of an animal from a large dose would indicate 

 that a 100 per cent mortality could not be expected. 



Since it is possible for liquid to be forced through the pyloris under 

 some conditions, these data have been checked against the results 

 of feeding experiments (Table 7). 



Table 7. — Intake by hungry white rats of food containing 5 or 10 per cent barium carbonate. 



Weieht of 

 rat. 



Amount 



Barium 



Barium 





of food 



carbonate 



carbonate 



Result. 



eaten. 



in food. 



eaten. 











]STg. per 





Grams. 



Grams. 



Per cent. 



kilo. 





295 



0.55 



5 



90 



Lived. 



159 



.20 



10 



125 



Do. 



185 



.25 



10 



135 



Do. 



184 



.50 



5 



140 



Do. 



167 



.25 



10 



150 



Do. 



286 



.90 



5 



155 



Do. 



174 



.30 



10 



170 



Do. 



198 



.35 



10 



175 



Do. 



292 



1.40 



5 



240 



Dead within 48 hours. 



310 



1.55 



5 



250 



Lived. 



215 



.55 



10 



255 



Do. 



192 



1.00 



5 



260 



Do. 



245 



1.40 



5 



285 



Do. 



330 



2.45 



5 



375 



Do. 



206 



1.55 



5 



375 



Dead within 24 hours. 



155 



.65 



10 



420 



Lived. 



291 



2.50 



5 



430 



Do. 



250 



2.25 



5 



450 



Dead within 40 hours. 



175 



.85 



10 



485 



Dead within 48 hours. 



343 



3.50 



5 



510 



Lived. 



148 



1.60 



5 



540 



Do. 



166 



1.85 



5 



555 



Do. 



188 



1.05 



10 



555 



Do. 



193 



2.40 



5 



620 



Dead within 16 hours. 



160 



1.00 



10 



625 



Dead within 72 hours. 



270 



3.60 



5 



655 



Dead within 40 hours. 



264 



3.50 



5 



655 



Do. 



215 



1.45 



10 



665 



Dead within 48 hours. 



280 



4.10 



5 



730 



Dead within 40 hours. 



320 



4.70 



5 



735 



Do. 



170 



2.60 



5 



765 



Do. 



252 



3.90 



5 



775 



Lived. 



366 



5.70 



5 



780 



Dead within 40 hours. 



175 



1.40 



10 



800 



Dead within 24 hours. 



215 



1.75 



10 



815 



Dead within 48 hours. 



205 



1.70 



10 



830 



Dead within 24 hours. 



167 



1.40 



10 



840 



Do. 



167 



1.45 



10 



870 



Do. 



150 



1.35 



10 



900 



Do. 



144 



3.60 



5 



1,270 



Dead within 20 hours. 



The results of these two sets of experiments, given in the order of 

 the barium carbonate intake per kilo, are in general agreement, the 

 efficient lethal dose of barium carbonate being 630 mg. per kilo, or, 

 more conservatively, 750 mg. On the basis of the barium content, 

 this preparation of barium carbonate was from 57 to 75 per cent as 

 potent as barium chlorid. In other words, approximately two- 

 thirds of the carbonate was utilized in poisoning the animal. This 

 does not mean, however, that every preparation of barium carbonate 



