2 DEPARTMENT OF AGRICULTURE. 



As many forms of contagious disease are supposed to be due to zymotic or fermentative 

 changes in the blood, in connection with which a microscopic cryptogamous vegetation is 

 constantly present in a growing condition, and as European and American microscopists 

 have asserted that this epizootic is a disease of this character, it became essential to the 

 success of this investigation that such microscopic examination should be skillfully made. 

 A request was accordingly made by this Department to Brevet Brigadier General J. K. 

 Barnes, Surgeon General United States Army, that Doctors J. S. Billings and E. Curtis, 

 assistant surgeons United States Army, might be authorized to assist Professor Gamgee 

 in his experiments upon the subject of the cryptogamic causes of disease. The Surgeon 

 General authorized these gentlemen to enter upon that duty, and their report is appended. 



The rapid extension of pleuro-pneumonia during the summer of 1868, and its increased 

 fatality at points where cattle were collected in numbers, made it the duty of the Depart 

 ment to ascertain its nature, extent, and the possible means of cheeking or -wholly 

 obliterating it. I therefore authorized Professor Gamgee, in the autumn of 1868, to make 

 a full investigation of the disease then spreading through many States of the Union. 

 In December of that year Professor Gamgee presented a preliminary report, which was 

 published in the monthly reports of 1868. His final report was first published with the 

 preliminary reports of cattle diseases issued in the autumn of 1869, of which this is an 

 enlarged edition. 



By the favor of Surgeon General Barnes, and under his direction, a further scientific 

 investigation of this disease has been made by Lieutenant Colonel J. J. Wood \vard, assistant 

 surgeon United States Army, whose report on the pathological anatomy and histology of 

 the respiratory organs in the pleuropneumonia of cattle, just received, is here presented, in 

 connection with six micro-photographs illustrating the condition of the diseased organs. 



Three chromo-lithographs accompany the report upon pleuropneumonia. 



These reports are followed by a statistical history of the splenic fever, or Texas cattle 

 disease, by J. R. Dodge, statistician of this Department, in which the devastations of this 

 peculiar and native malady arc unmistakably traced back into the eighteenth century. 



It need not be presumed that these investigations are conclusive or final ;. on the 

 contrary, some practical problems not yet fully demonstrated urgently demand examina 

 tion. Among these are the best mode of arresting contagion and the proper regulation of 

 cattle transportation northward. A general law in the interest of the public health, of an 

 enlightened humanity, and of the cattle trade, should regulate the transportation of cattle, 

 not only from the Gulf State3, but on the great eastern routes and throughout the country. 



HORACE CAPRON, 



Commissioner, 



Hon. SCHUYLER COLFAX, 



President of the Senate. 



