350 Ibervillea Sonorae 



Although it did not seem probable that the observed cathartic 

 action could be due solely to the small amounts of compounds of 

 the alkali earth metals that were present, we tested the effects of 

 the ash in some experiments of which the following, as described 

 in our records, is an illustration. 



Tests of the effects of tuber ash given by mouth to dogs. Tenth experi- 

 ment. Weight of the dog, 7.22 kilos.' On the first day of the experi- 

 ment the animal was given 0.6 gram of ash corresponding to the inorganic 

 matter in about 4 5 grams of tuber. Thiswas administered in several small 

 balls of meat. No other food was given that day. There were no ap- 

 parent effects. On the following day the fast was continued and an equal 

 portion of ash, i. e., 0.6 gram (which had been largely converted into chlorid 

 by treatment with hydrochloric acid, with subsequent removal of the acid 

 by evaporation to dryness) was dissolved in distilled water and admin- 

 istered by means of a stomach tube. This also failed to produce any 

 noticeable effects. The dog was apparently normal in all respects during 

 the three succeeding days, after which he was no longer kept under 

 observation. 



The results of the experiments in this series also fail to explain 

 the effects caused by the tuber. Unfortunately, our supply of 

 tubers was exhausted at this point and further study had to be 

 given up. 



VII. GENERAL CONCLUSIONS. 



Besides yielding the data for composition of Ibervillea SonorcB, 

 our study indicates that the tuber does not contain alkaloidal 

 material, or at least not in sufficient proportion to cause particular 

 toxicity. We have not learned the reason for the cathartic effects 

 exhibited by the tuber or its decoctions. 



We wish to thank Dr. Gies for his kind guidance and advice in 

 this study, and also for his assistance in carrying out the work. 



1 Daily diet — hashed meat, cracker meal, lard and water, with macer- 

 ated filter paper to make the feces bulky and approximately normal in 

 consistence. For this purpose bone ash was avoided in order to give the 

 tuber ash full opportunity to display its greatest possible toxicity, without 

 unnecessary interference. A preliminary period of five days established 

 normal conditions. 



