308 BOARD OF AGRICULTURE. [Pub. Doc. 



calves obtained from various sources in an investigation of 

 vaccine virus. Dr. Tyzzer has kindly made a report of his 

 observations and further experiments tried at the expense of 

 the United States Department of Agriculture, which were 

 undertaken to ascertain the correctness of the view^ that the 

 disease could be carried by contaminated vaccine virus, and 

 which fully proved the correctness of this supposition. Dr. 

 Tyzzer's report will have to be considered in two parts ; the 

 first relating to the experiments at his father's farm, and the 

 consequences ; the second giving the experiments tried at 

 the Newcomb estate, in Wakefield, which was hired b}' the 

 United States Department of Agriculture for this object, 

 and where experimental animals bought for the purpose at 

 Brio'hton and Somerville were taken. The Newcomb estate 

 is a place near Wakefield Junction, where the house had 

 been burned, upon which there was a small stable where no 

 cattle had been kept for a long time, and which, from its 

 isolation, seemed suitable. The experiments at the New- 

 comb estate were carried on by the United States Bureau of 

 Animal Industry in conjunction with the Cattle Bureau of 

 the State Board of Agriculture, and with Dr. Tyzzer's assist- 

 ance, who repeated the experiments with vaccine virus ex- 

 actly as he had conducted them at his father's farm. 



REPORT OF DR. ERNEST E. TYZZER. 



Part I. — Experiments preceding the Outbreak of Foot and 

 Mouth Disease in Wakefield. 



In the followinsr brief account it is intended to cover the essen- 

 lial facts regarding the experiments which preceded the appearance 

 of foot and mouth disease among the cows of G. R. Tyzzer of 

 Wakefield, Mass., on the 21st of August, 1903. 



Being engaged in the study of vaccine with reference to its 

 pathology, 1 purchased a number of calves and kept them in a 

 portion of my father's (G. R. Tyzzer) barn. Vaccine lesions at 

 various stages of development were desired. It was intended in 

 these experiments to vaccinate the calves at various points on the 

 surface of the body, and to kill them at different intervals of time 

 after vaccination, in order to obtain the lesions. Au account of 

 each experiment will be given below. 



The ordinary commercial vaccine lymph was not used for these 



