So long as the disease lasts is this application to be applied, limited certainly to the extent of the eruption; as long as this treatment is being adopted, not a drop of water should be allowed to touch any part of the skin surface (no washing of any sort) until healthy action of the skin has set in, recognised by the falling off of the crops of scabs, without any raw, ulcerated surfaces. Is there any danger to the patient from the absorption of the carbolic acid into the system? So long as the oily solution is used, and no water allowed to come into contact with the skin, I consider there is little or no danger, but it is necessary _always to be careful_. Should the patient be suffering from the absorption of the carbolic acid, you will find a cold, clammy skin, rapid fall of both temperature and pulse, and the urine of a smoky _greenish-brown_ colour, and having the odour of carbolic acid. In many cases of small-pox, but where no carbolic acid has been employed, the urine becomes smoky-brown, but it has not the peculiar greenish tinge of where carbolic acid is present. To judge the odour correctly, the urine should be put into a fresh dish and examined in some other room, or, what is better, the open air, so that there can be no mistake, as the air of any house gets so saturated with the odour of carbolic acid that it is not easy to judge whether the odour is that of the air or of the urine. If danger from excess of absorption of carbolic acid is feared, do not give up the treatment, but lower the strength of the carbolic acid in the oil to 1 in 20, and more or less limit the number of the applications. But what is far more important, see that there is abundance of ventilation in the room. I would fear more from a close chamber and excess of carbolic acid vapour in the air than the possibility of the excess of acid having been absorbed from the oil. Remember you are not dealing with a _watery_ solution where there, I believe, _is danger_, as water, besides quickly evaporating, rapidly yields up its carbolic acid to the tissues, which too readily absorb it. Oil but slowly evaporates, and with difficulty parts with the carbolic acid it holds in solution to the tissues. All the swabs, mops, &c., of cotton-wool, and the wool itself that may have been employed in treating a case, should be burnt at once when they are no longer required. The blankets and bedding, after a good washing and exposure to sun, will be found to be free of infection, and may be again with safety employed. Upon the above principles I have treated the vesicle of vaccination, with much comfort to the patient, and in most of the cases entirely prevented the pustular stage. AITCHISON. APPENDIX D. THE CLINICAL THERMOMETER.