86 Bulletin No. 207. 



weight 750 pounds, received a similar amount of the nitrate in 

 wholesome oats (Fig. 33). Control horses Nos. 109, 110, and 

 114 all succumbed, No. 109 on March 31st, No. 110 on April 2nd, 

 and No. 114 on April 7th. 



The clinical symptoms observed in the control horses in 

 this experiment were similar to those in horses that succumbed 

 as the result of feeding the organism in unfiltered broth cul- 

 ture. A detail of the symptoms displayed from day to day 

 by the control animals is not presented, but, with variations, 

 these animals showed clinical manifestations recognized in forage 

 poisoning, terminating fatally in each animal at the time in- 

 dicated. The gross anatomic lesions likewise closely resembled 

 those observed in forage poisoning; a detail of each animal is 

 therefore omitted as similar symptoms and anatomic altera- 

 tions have been recorded in other horses fatally afflicted. The 

 four serum treated horses receiving portions of the same whole- 

 some rations each day displayed no symptoms and were released 

 after a period of 21 days (Fig. 34). 



The result from the feeding of the nitrate, together with 

 the simultaneous injection of prophylactic antitoxin, as briefly 

 presented, is contributive to our knowledge of the anaerobic 

 bacillus isolated from the oat hay water. 



The Relation of Botulism Antitoxin to the Etiologic 

 Factor in the Oat Hay. 



The toxic effect of the water soluble products of the oat 

 hay, as observed in horse No. 91, has been mentioned. It is 

 evident, if a number of horses were allowed to drink from the 

 barrel, that large amounts of fresh water would have to be 

 added each day to replace the amount consumed. Such pro- 

 cedure would eventually extract and dilute the soluble poisonous 

 products in the oat hay. The water was removed from the barrel 

 in three-gallon buckets and a number of horses were supplied 

 daily. An equal amount of fresh water was simultaneously 

 returned to the barrel each day and allowed to remain in con- 

 tact with the oat hay approximately 10 to 12 hours before re- 

 moval. No restriction was placed upon the amount of water the 



