502 EXPERIMENT STATION RECORD. 



It is a matter for congratulation, therefore, tliat the cause of the 

 poisoning and the reason for the variation in this respect now appear 

 to be exphiined by studies which have been going on in the Bureau 

 of Animal Industry of this Department, under Dr. John R, Mohler, 

 and are now announced in a preliminary way. The laborator}^ and 

 pharmacological studies have been conducted by Dr. Albert C. 

 Crawford, who in an article which has just appeared describes the 

 method of procedure which was followed in studying this problem, 

 and iiresonts his deductions as to the causative agent." 



To the surprise of many, Dr. Crawford finds the poisonous princi- 

 l)le not to be an alkaloid, and probably an inorganic rather than an 

 organic body — a salt of pyrophosphoric acid. Phosphoric acid has 

 long been known to be present in cotton-seed meal in considerable 

 quantit}', and has been suggested as having a possible relation to its 

 toxicity ; but the methods of study followed have not been such as to 

 bring out this relationship or lend support to the hypothesis. 



Dr. Crawford's results seem conclusive, and are supported by a 

 large amount of data from a systematic series of laboratory studies 

 and physiological tests. The findings have been confirmed by feeding 

 experiments with pigs, carried out b}^ the Bureau, which are not 

 presented in the preliminary paper. These feeding and pathological 

 studies, together with the laboratory investigations, are to be pub- 

 lished later as a bulletin of the Bureau. The preliminary notice is 

 issued at this time because of the interest in the j)rogress of the 

 work which has been manifested by several of the experiment sta- 

 tions now engaged in studying the prolilem. The present account is 

 sufficiently detailed and comprehensive to indicate the character and 

 scope of the investigation, and it will make it possible for other 

 investigators in this field to redirect their studies and to coordinate 

 them with those of the Bureau. 



Starting with the product which would be digested by the animal, 

 that is, the extract prepared by digesting cotton seed with pepsin 

 and jDancreatin, the extract was concentrated and studied in its toxic 

 effects on rabbits. Whole cotton seed of known origin was used in 

 a number of cases, which was first ground and extracted to remove 

 the fat. The same variations in toxicity which had been noticed in 

 other experiments were encountered. It was found that while the 

 seed from Upland cotton was quite generally poisonous to animals, 

 that from certain Sea Island cotton contained so small a quantity of 

 the poisonous principle as to be practically harmless. The toxic effect 

 of the Sea Island seed, however, was greatly increased by heating, 

 indicating that if in the treatment of the seed at the oil mills the 



« Jour. Phanuacol. and Expt. Tber., 1 (1910), No. 5, pp. .519-.54S. 



