CHARCOAL possesses the power of absorbing gases in large quantities in vastly greater proportions than the relation of its bulk. It con- denses the gases within its pores. It does not act equally upon all gases in this way ; absorbs but little hydrogen ; more oxygen ; large quantities of sulphuretted hydrogen, and still more of ammonia. It is used as a disinfectant and to purify water; to remove the foul smells from ulcers, etc. It is inferior as a disinfectant to volatile substances, because it can act only on the air which comes in contact with it. Not so good in poultice on sores as in bags, dry and granulated. It is used in the old practice to relieve heart- burn, flatulence, etc. In dose, six to ten grains. Hahnemann says: "The disinfectant action of Carbo vegetabilis is purely chemical. The mouth rinsed with charcoal and made sweet soon becomes foul again. So do the ulcers and the excretions treated with charcoal. It is not," he continues, "until charcoal has been reduced to a state of minute subdivision by trituration, according to the 326 CARBO VEGETABILIS. rules of homoeopathic pharmacy, that it produces specific effects upon the organism." The proving which Hahnemann presents us was made with the third centesimal trituration. These symptoms may be summarized as fol- lows :