410 CAEBOLIC ACID 



ferments, or in killing or preventing the development of 

 bacteria ; but Koch's experiments show that about one part 

 to 500 prevents the growth of anthrax and other bacilli. 

 Oats, barley, beans, and lentils, soaked in a one per cent, 

 solution, do not germinate. Milk is maintained unchanged 

 by ^th part of acid. The bacilli of tuberculosis are killed 

 in twenty-four hours by a 5 per cent, solution. The de- 

 velopment of putrefactive organisms is arrested by a 4 

 per cent, solution which is also fatal to the organisms of pus. 

 Warm aqueous solutions are more powerfully antiseptic 

 than solutions in alcohol, oil, or glycerin ; in fact, carbolised 

 oil is only feebly antiseptic and not reliable as a disinfectant. 

 The probable reason for this is that phenol is so readily 

 soluble in oil that it will not leave the oily solvent to attack 

 the protoplasm of the bacteria. As carbolic acid gradually 

 volatilises, not only may fresh infection occur, but spores 

 and organisms, the development of which has been arrested, 

 may regain activity. 



A strong solution applied to the skin, or to a mucous 

 surface, coagulates albumin, acts as a topical irritant and 

 slight caustic ; anaesthetises not only the skin, but the 

 underlying structures ; causes a stain at first white, but 

 shortly becoming brown ; and leaves a dry, roughened 

 surface, from which the shrivelled epidermal scales subse- 

 quently peel off. 



Full doses when swallowed, besides producing local effects, 

 cause salivation, and in carnivora usually vomiting, with 

 gastro-enteritis and collapse from shock, which may end 

 fatally. It is absorbed, and like other members of the 

 benzol series, in small doses, it first very briefly stimulates 

 and subsequently paralyses the medulla and spinal cord, and 

 involves also the cerebral centres. The respiratory and 

 vaso-motor centres are first stimulated, quickening respira- 

 tion, raising blood-pressure, and accelerating the pulse ; 

 but as paralysis is developed, respiration is slowed, and blood 

 pressure falls. Stimulation of the sweat-centre increases 

 perspiration. Implication of the cerebral centres gives rise 

 to restlessness, irregular movements, convulsions, and 

 anaesthesia. These symptoms are followed by depression, 

 weakness, staggering gait, then collapse and coma. Moderate 



