Dermatology

There are certain conditions of the skin where there is extreme hypersensibility to external agencies, e.g. to the actinic rays of light. In order to try to desensitise the tissues the injection of fresh serum from the patient has been tried. Hilario (Journ. Cut. Dis., 1914, p. 780) reports considerable success by this method. Blood is collected from a vein by a sterile needle into a sterile 50 c.c. glass vessel with cotton-wool stopper. It is kept in a cool place till it clots. The clot is then separated from the wall of the container by a sterile pipette, and the vessel placed in an electric centrifuge revolved at a speed of ?3000 revolutions per minute. After 15 minutes in the centrifuge a clear serum can be obtained. The serum is decanted off into a 30 c.c. syringe and injected intravenously. The injection should be done slowly and repeated once a week. An hour to an hour and a half is required from the time the serum is withdrawn till it is restored to the patient. The blood should be allowed to clot thoroughly before centrifuging, as otherwise some haemolysis may take place, and the