No. 4.] STABLE MANAGEMENT. 189 



sent to a neighborhood, and they take one, two or three 

 herds and rid them of all disease. There is a herd across 

 the street that is badly diseased. What are the liabilities 

 of these cattle which have been freed from the disease 

 taking the disease from the cattle across the street ? 



Dr. Osgood. Exposure to direct rays of sunlight is 

 almost sure death to the germs. The danger of the trans- 

 mission of the disease from one side of the street to the 

 other through the medium of the atmosphere I do not think 

 is worth considering. Probably the common cause of the 

 spread of the disease is from the dry bacilli of the disease 

 being inhaled by other animals. 



Mr. Bradley. It is not transmissible through the moist- 

 ure of the discharges ? 



Dr. Osgood. It can be transmitted by the moist dis- 

 charge, but by the law of gravitation it falls to the ground, 

 and is not likely to rise until it becomes dry. It is not so 

 likely to be transmitted in that way as it is to be inhaled in 

 the dry form. 



Mr. Bradley. In the spring of the year, when our cattle 

 are in the streets, being driven to and from pasture, are they 

 liable to take the disease from other cattle, which are driven 

 over the same road, that are diseased? 



Dr. Osgood. I think the chances would be small. Fif- 

 teen minutes of sunlight is usually sufficient to destroy the 

 bacilli in the discharge. 



Mr. Pratt. How long after applying tuberculin to a herd, 

 and finding it perfectly sound, do you wait before applying 

 it the second time ? 



Dr. Osgood. One illustration : we tested, eighteen 

 months ago, a herd consisting of seventy-five animals ; 

 thirty-five of them were found to be diseased, and were 

 killed. A month ago, seventeen months after, I retested 

 the herd, and not a reaction. I can cite to you four or five 

 stables that have gone that length of time without any trace 

 of the disease. I went through the herd, and every animal 

 that reacted I killed. Any animal that showed the least evi- 

 dence of a deviation of temperature I put one side. All those 

 that there was a particle of doubt about, those that we could 

 not determine, we destroyed. Those that we were certain 



