IMMORTELLES 127 IMPEACHMENT must be considered a religious convic- tion. Among rude peoples the life after ^ath is usually regarded as a state of being not essentially different from the present — one in which the hunter will re- new his chase, and his corporeal senses shall have their accustomed gratifica- tions. Among the ancient Greeks and Romans the spirits of the dead were be- lieved to live in the other world as a sort of shadows, and the life after death was also considered as a shadow of the present. IMMORTELLES, a name for flowers, also known as everlasting flowers, and often made into wreaths for adorning graves. IMMUNITY, in medicine the name given to a condition of the living body in which it is safe from the attacks of par- ticular infectious germs, or certan pois- ons. Although the phenomena of im- munity occur in cases of several vege- table and animal poisons (ricin, and snake venom for instances) not asso- ciated with disease, and are, hence, not strictly limited to the infectious diseases, they are of chief prophylactic and thera- peutic interest in connection with the latter group of maladies. In a region where yellow fever abounds, certain in- dividuals remain healthy, while their neighbors fall victims to the fever. These persons are spoken of as im- munes. Their immunity may be due to a natural insusceptibility, or may have resulted from a preceding attack of yel- low fever. One attack of many of the infectious diseases confers immunity from any further attacks by the same germ. This fact, long ago noted by the medical practitioner (and utilized for the prevention of smallpox in China several hundred years ago), is now being applied in prevention and curative work in the case of many common infectious dis- eases — typhoid fever, cholera, plague, cerebrospinal meningitis, etc. The im- munity conferred upon person by an at- tack of disease is called active; that resulting from an artificial treatment with vaccines or sei'a, -passive. The remedies used in producing artificial im- munity are called vaccines, antitoxins and toxins. Vaccines usually consist of living or dead bacteria or their poisons (toxins) ; sometimes the living organisms are weakened or attenuated by heat, growth on special culture media, passage through other animals, etc., before use in the human body. The injection of vac- cines, in small, frequently repeated doses, stimulates the normal protective agencies of the body. If the special disease germs, for which the vaccine is intended, are present in the body, in other words if the man already has the disease, the vaccine serves as an aid to the regular body forces, in raising a defensive army. If the disease is not present, the vaccine builds up a condition of immunity, so that an attack by the germ, if it occur; at a later period, can be warded off. Vaccines have been more successful as preventives than as cures. The immu- nity produced may be permanent and lasting or merely temporary, a few weeks or months. Antitoxins are substances which act as antidotes to the toxins pro- duced by disease germs. They are com- monly manufactured by repeatedly in- jecting in an animal (horse, goat, dog, etc.), with increasingly virulent doses of the organism or its poisons against which an antitoxin is desired. The animal's blood finally becomes highly re- sistant to this particular organism, and it can withstand without harm many times the dose of germs fatal to a similar animal not so artificially immunized. A portion of the blood of the immunized animal is drawn, and the serum obtained from this constitutes the essential ele- ments of the commercial antitoxin. IMPASTO, in painting, a term used to express the thickness of the layer or body of pigment applied by the painter to his canvas. According to the method of handling exercised by different artists, this impasto is thick or thin. Rem- brandt, Salvator Rosa, and others used a thick impasto; Raphasl, Guido, and others, an impasto so thin that threads of the canvas and the crayon outline may be seen through it. IMPATIENS, a genus of Balsamina- cese, with the calyx and corolla so ab- normal that it is difficult to discriminate the several parts. About 135 species are known, nearly all from the Hima- layas and other Indian mountains. The distilled water of the yellow balsam, taken in large quantities, is said to bring on diabetes. IMPEACHMENT, the act of accusing, or charging with a crime or misde- meanor; the arraignment of a minister of state for maladministration or trea- son. In England impeachments are made in the House of Commons, and tried by the House of Lords. The Constitution of the United States provides that the House of Representa- tives shall have the sole power of im- peachment; and that the Senate shall have the sole power to try all impeach- ments. Section 4 of Article II. provides that the President and Vice-President and all civil officers of the United States
