Julia T. Emerson and William H. Welker 347 



by aqueous extracts of certain plants and even by shreds of filter 



paper.' 



Physiological tests. Toxicity of the residues obtained by the 

 method described above was determined by dosing a 2.7 kilo 

 female pup as follows: 



Administration per os: 1st day. The dog was given in one meal daily 

 an ordinary quantity of food consisting of meat, cracker meal, lard, bone- 

 ash and water. The weight of the residue given the first day was 0.0523 

 gram. It was placed inside of a ball of meat and in this condition swal- 

 lowed without mastication. Except very slight diarrhea during the fol- 

 lowing night, no effects were observed. 



2d day. On the second day of the experiment 0.1046 gram of residue 

 was administered in the food as before. Slight diarrhea, about nine hours 

 after feeding, was the only apparent effect of the material. 



Sd day. On the third day the animal was apparently perfectly normal, 

 and accordingly a study of the effects of subcutaneous injections of the 

 material was begun on the following day. 



Subcutaneous injection: 4th day. The animal appeared to be normal 

 in all respects. About 0.05 gm. of residue was dissolved in 3 to 4 cc. of 

 alcohol, and injected on the right side. No general effects whatever were 

 observed during the following twenty-four hours. 



5th day. On this day about o.i gram of residue was injected in 3 to 4 

 cc. of alcoholic solution. No symptoms of any toxic action were observed 

 during ten hours following the injection. A small abscess formed at the 

 point of injection; otherwise the animal apparently remained normal 

 during the next two days, when observation was discontinued. 



These tests failed to show the presence in the extracted mate- 

 rial of any known alkaloid or alkaloids. The physiological tests 

 indicated further that, if any alkaloid was present, its propor- 

 tionate content was too slight to enable it to exhibit distinct or 

 characteristic effects. 



Tests of the effects of hashed tuber given by mouth to dogs. The 

 results of the foregoing toxicological tests suggested either that 

 our extracts did not contain the toxic principle of the tuber or 

 that the reputed poisonous action of the tuber is due to some 

 compound other than an alkaloid. To decide this question, a 

 number of special experiments on toxicity were conducted. 



Two tubers were rapidly peeled, sectioned and hashed. The interior 

 of one of them was found to be full of small brown masses. The other 



1 Wormley: Micro-chemistry of Poisons, 2d ed., p. 589, 1885; Sedgwick: 

 Anter. Chem. Jotirn., p. 369, 1879. 



