Having adopted all these precautions the Mohel may be confident that in regard to his own hands, the instruments, and the dressings he has exercised every care which surgical science demands. The only other important detail which demands attention is the part concerned in circumcision. It is obvious that all the safeguards hitherto considered are valueless unless the infant himself is in a perfectly clean condition. The disinfection of the skin of an adult before an operation is always a serious and difficult matter, because the skin harbours so many micro-organisms, including the very micro-cocci referred to previously. Elaborate measures are therefore employed for the skin disinfection. But in the case of an infant the skin cannot be supposed to be such a probable source of wound infection. It is sufficient that the genitals be washed about half an hour before circumcision, with soap and warm water, and subsequently a fomentation of Boracic lint applied. It is as well to avoid the use of the various baby powders which nurses are so fond of sprinkling freely on the folds of the skin. If it is thought desirable to employ such a dusting powder, it should be a mixture of equal parts of Boracic Acid and Starch. The infant having been prepared as here stated, the circumcision may proceed as soon as he is put in position. Should any soiling have taken place, the infant must again be cleansed, and in this case the genitals must be washed with the Carbolic Acid solution (1 in 40) by means of a swab of cotton wool. [Illustration] CHAPTER IV. _Surgical Anatomy._ It is essential for the Mohel to possess a knowledge of the structure of the organ on which he operates. The skin of the penis is continuous on the upper surface with the skin of the abdomen, and on the under surface with that of the scrotum. On drawing forward the prepuce or foreskin it is very easy to include the skin of the scrotum in the grasp of the fingers unless due care is taken. If the traction on the foreskin is too forcible and the skin of the scrotum is therefore pulled up tightly, there is a danger of the scrotal skin being slit up to some extent. The intimate connection of the skin of the penis and scrotum must always be kept well in mind. Under the foreskin and continuous with it at its free margin there is a membrane which rising from the neck or constriction below the glans envelops the latter entirely up to the opening of the urethra. Here it leaves the glans and joins the outer skin. The name given to this structure is _mucous membrane_, and the method of dealing with it constitutes the principal portion of the art of circumcision. This mucous membrane is the whitish glistening structure which appears after the removal of the skin. It is important to note the disposition of this mucous membrane, as revealed after the amputation of the prepuce. 1) It usually _covers over the glans right up to the orifice of the urethra_.