Because charcoal can pack molecules of ammonia gas into its crevices, it can attract and hold 80 quarts of ammonia gas per one quart of pulverized charcoal! This process is called adsorption, or attaching onto rather than taking onto rather than taking into as in absorption.
In 1733, Scheele made an experiment with charcoal in which a gas was trapped in an inverted tube with charcoal, the lower end of the tube being submerged in a container of mercury. As the gas was adsorbed by the charcoal, a vacuum appeared in the tube and sucked the mercury up into the tube.
Pharmacist P.F. Touery, in 1831, making a demonstration of the effectiveness of charcoal before the French Academy of Medicine, survived after swallowing 15 grams of strychnine (ten times the lethal dose) and an equal amount of charcoal—about three tablespoonfuls.
Charred toast and other scorched food in the kitchen are not healthful. They are not charcoal. These represent charred protein, fats, carbohydrates, and mineral salts, the very parts burned away in charcoal, leaving only charred cellulose.
The skeletal structure remaining in true charcoal is inert, where as the remaining substances in charred food can react unhealthfully with the body, and even act as cancer-producing agents.
Activated charcoal is produced from the controlled burning of wood or bone which is then subjected to the action of an oxidizing gas such as steam or air at elevated temperature. This process enhances the adsorptive power of charcoal by developing an extensive network of fine pores in the material.
The activation process was not invented until after the turn of the 20th century, but charcoal was already recognized as a useful healing agent even though only regular charcoal was then in use.
Following activation of charcoal with pressurized steam or strong acid, the surface area of one cubic centimeter is 1000 square meters!
This expanded surface is due to the fact that charcoal particles have thousands of crevices, pits, grooves, and holes which, when opened out, make quite a large surface area.