Читать книгу Special Report on Diseases of Cattle - Lowe - Страница 56

To define clearly the meaning of the word "poison" is somewhat difficult. Even in law the word has never been defined, and when a definition is attempted we are apt to include either too much or too little. The following definition given by Husemann is perhaps the best: "Poisons are those substances, inorganic or organic, existing in the organism or introduced from the outside, produced artificially or formed as natural products, which, through their chemical nature, under definite conditions, so affect some organ of a living organism that the health or well-being of the organism is temporarily or chronically injured." The common conception of a poison is any substance which, in small quantity, will destroy life, except such as act by purely mechanical means, as, for example, powdered glass.

Some substances that are not usually looked upon as poisons may destroy life if given in large doses, such as common salt. Other substances which are perfectly harmless when taken into the body in the usual way are poisons if injected into the circulation, such as distilled water, milk, or glycerin. Living organisms are not "chemical substances," and are not considered in this connection.