I found the general period of incubation from five to six weeks. I have taken the greatest pains with the byres where the infected cattle stood, having the wood-work taken out, the roofs and greeps carefully scraped and washed with soap and warm water, lime-water, and afterwards with chloride of lime; and yet, after all this labour, I have seen the disease break out again and again. After repeated outbreaks, I not only removed the wood-work, but the whole of the stones in the stalls and greeps, and buried them. I had the roofs and stone mangers, &c., carefully scraped, and washed with soap and warm water, and afterwards with chloride of lime. They were then closely painted, and lastly coal-tarred; but it was only after five or six months' perseverance that I got clear of it. Having heard a report that a cow belonging to my cousin, Mr M'Combie, editor of the 'Free Press,' was labouring under pleuro-pneumonia, I went to see her. Mr Sorely, veterinary surgeon, was in attendance. As there had been no disease in the neighbourhood for five years, I was unwilling to credit the report. But a more marked case I have never witnessed; and the _post-mortem_ examination showed all the symptoms of the fell disease. Mr Sorely, Mr M'Combie's overseer, and I, all agreed that as a wood dividing-partition had been allowed to remain since the time of the previous infection, and the cow was seen chewing pieces of the wood that had got rotted at the base, the wood had retained the poison, and the cow had been infected from the chewing of it. The breath is the cause of the infection when cattle are housed together and the disease introduced. It generally attacks the animals standing at the walls first. The breath is driven by different currents through the building to the walls, where it is stopped; it rebounds, and hence the beasts at the walls generally fall the first victims--so, at least, I have found it in my experience. I had forty beasts divided by a stone-and-lime mid-wall to the level of the side-walls; up to the roof there was a strong and close division of wood. Unfortunately there had been a small aperture about two feet square left open. I made an observation to the cattleman that I should not be at all surprised if the disease came from the infected byre through the opening to the byre where the cattle were sound. The first or second day thereafter the animal standing below the aperture was seized, and got down in the disease.