Julia T. Emerson and William H. Welker 349 



A. 1st day. Five grams of "spotted" tuber were given without effect. 

 The feces passed this day were hard and dry. 2d day. Ten grams of 

 tuber were given. There were no apparent effects, ^d day. Twenty 

 grams of tuber were administered in gelatin capsules. This dose also 

 failed to produce any toxic symptoms. The feces remained hard and dry. 

 ph day. Forty grams of tuber were given in capsules as before. Appar- 

 ently no effects were produced. 5//1 day. Fifty grams of tuber were 

 given at noon in capsules as before. Slight diarrhea occurred during 

 the afternoon and evening, while marked diarrhea ensued between mid- 

 night and 8 a.m. The dog was apparently normal at 9 a.m. 6th day. 

 The regular diet was fed without the tuber. 



B. yth day. Twenty-five grams of rind were given in gelatin capsules 

 with the regular diet. Very marked diarrhea occurred about six hours 

 later. The dog seemed normal on the following morning. 8th, gth and 

 lOth days. The dog was fed the usual diet without any rind, iith day. 

 Twenty-five grams of rind were given in capsules without producing any 

 apparent effect. 12th day. Twenty-five grams of rind were given. Three 

 hours later marked diarrhea ensued. This was followed by the vomiting 

 of undigested meat, i^th day. The animal fasted, iph day. A small 

 meal was fed in the afternoon, i^th day. Twenty-five grams of rind were 

 given in capsules with the regular diet at 10 a.m. Diarrhea occurred 

 between 8 and 8:45 p.m. By the following morning the dog had appar- 

 ently recovered. 



These experiments and the remaining ones of the series made 

 it evident that the toxicity and even the cathartic effects of 

 Ibervillea SonorcB, as measured by results on our dogs, have per- 

 haps been overrated. In some instances, comparatively large 

 quantities of the hashed tuber or the rind were entirely devoid of 

 obvious effects. The "spotted " tuber was no more (but perhaps 

 less) toxic than the normal tuber. These results were also in 

 accord with our previous conclusion that there is little if any 

 alkaloid present in the tuber. 



Although the toxic and cathartic effects were relatively slight, 

 it was thought that possibly oxalic acid was present in sufficient 

 proportion to share in producing the effects noted. Analysis of 

 a fresh portion of tuber made it evident, however, that the 

 proportion of oxalic acid in the tuber was very slight. 



It also seemed possible that magnesium salts might have par- 

 ticipated in the cathartic effects observed. Partial quantitative 

 analysis of the ash gave the following percentage results: CaO, 

 23.76; MgO, 15.62; CO2, 13.92; CI, 11.96; P2O5, 8.1. Sodium and 

 potassium were present in abundant proportions. The propor- 

 tion of ash in the fresh tuber was only about 1.4 per cent. 



