484 HEALTH AND DISEASE 



so, that there is at the present time hardly an organ in the body to 

 which the surgeon's knife has not safe access, and whose disease it does 

 not challenge. 



In the use of antiseptics for surgical purposes, they are not only freely 

 applied to wounds, but also to the instruments to be used in operating 

 and the hands which use them, and may be also to the air of the apart- 

 ment in which operations are carried out. 



Surgeons distinguish between agents which merely prevent the develop- 

 ment of pathogenic organisms and those which actually destroy them. 



One of the most valuable antiseptics is carbolic acid. 



Carbolic Acid. This is a product of the distillation of coal-tar, and 

 is chemically known under the several names of phenic acid, phenol, and 

 phenylic alcohol. The colourless, needle-shaped crystals of pure carbolic 

 acid are not convenient for surgical purposes unless broken down with 

 glycerine or some other solvent. A comparatively impure acid is equally 

 efficacious, and in general use more economical and convenient. The 

 preparations of value to the veterinarian are glycerine of carbolic acid, 

 carbolic lotion, carbolic ointment, and carbolic oil. 



Carbolic acid is both a disinfectant and an antiseptic, and though only 

 mixable with or soluble in water to a small extent, it can be made more 

 so by the addition of glycerine, and is then employed in different propor- 

 tions for a great variety of purposes. Strong solutions destroy living 

 organisms, while dilute preparations merely prevent their growth. Besides 

 being an antiseptic, carbolic acid is also a caustic when applied undiluted 

 to the skin, leaving a white mark as evidence of the superficial layers 

 being destroyed. Acute pain is felt at the moment of application, but 

 the sensibility of the integument is subsequently diminished. 



It is a valuable agent in the treatment of ulcers, cracked heels, and 

 such diseases. Ringworm and other affections having their origin in 

 low forms of life are successfully combated with strong carbolic appli- 

 cations, which are mostly made in the form of an ointment. Some 

 forms of skin irritation arc allayed by weak lotions of carbolic acid, 

 while the mange mite and other external parasites are either imme- 

 diately killed by it or caused to quit the body of their host. 



Applied internally, it is a safe and useful agent in the treatment of 

 those ulcerative conditions which affect mucous membranes, more espe- 

 cially those of the nostrils, mouth, throat, and other parts accessible to 

 the surgeon. 



The foetor of the breath arising from dental troubles, and referred to 

 at some length, . is subdued by a suitable mouth- wash in which carbolic 

 acid is the active ingredient. 



