SECRETARY'S REPORT. 15 



No. 2, (Maine,) which had escaped two previous exposures, were found 

 diseased. In short, four of the six exposed have certainly contracted 

 the disease, and it is not certain that the other two have not. 



It is evident from the foregoing that two points have been established. 



1st. Tliat the disease is contagious. 



2d. That it is more surely communicated by affected animals in the 

 early stage of the disease than at a later period. 



PATHOLOGICAL ANATOMY. 



I know of no author who has distinctly stated that there are anatom- 

 ical changes in the disease called pleuro-pneumonia which is contagious, 

 and the ordinary disease of the same name. From my own observa- 

 tions, in a somewhat extensive practice among cattle, extending over 

 a period of fifteen years, but few cases of acute disease of the lungs 

 have occurred. In one which I treated in 18G1, which proved 

 fatal, an examination was made. (A well marked case of pleuro- 

 pneumonia.) 



The autopsy showed inflammation of the pleura, effusion of serum 

 into the thoracic cavity, solidification of the lung, without the thickened 

 interlobular tissue. 



The lungs of a cow that died of pleuro-pneumonia, in Needham, were 

 brought to me for examination. The pleura was inflamed, the lower 

 third of the lung was hepatized, solidified, yet on cutting tlu-ough it there 

 was not the infiltrated, thickened, interlobular tissue found in the other 

 form of the disease. 



A coAV belonging to the pauper establishment at East Douglas was 

 sick and died. As the symptoms resembled those described as existing 

 in contagious pleuro-pneumonia, the commissioners were requested by 

 the selectmen to visit Douglas. The carcase was exhumed and the 

 Imigs taken out. On examination both lungs Avere found diseased ; a 

 large part of one lung and a portion of the other was hepatized, but the 

 marbled aspect caused by the dark red spots and the yellowish white lines, 

 was not present. 



No other animals having been attacked in either of the two herds 

 alluded to, it is fair to presume that both had a different kind of disease 

 from that under consideration. 



In a work published in 1840, (two years before the contagious pleuro- 

 pneumonia broke out in England,) by the Society for the Diffusion of 

 Useful Knowledge, edited by Mr. Youatt, is a description of acute and 

 epidemic pneumonia, in which he says : " On examination after death 

 the lungs are gorged and black with blood ; they are softened and easily 

 torn; they however contain some spots of hepitization, or condensed 

 substances, and often abscesses . filled with pus. The pleura, the 



