There seems to be a balance maintained between the restriction of disease by prevention and the increased influence of social conditions which are in themselves factors of disease.  Preventive medicine seems to have made possible, by restricting their harmful influence, the increase in industrialism, in urban life, and in the intercommunications of peoples.  The most important aid in the future to the influence of preventive medicine must be the education of the people so that the conditions of disease, the intrinsic and the extrinsic causes and the manner in which these act, shall all become a part of general knowledge, and the sympathy of the people with health legislation and their active assistance in carrying out measures of prevention may be obtained.  The effect of social conditions on disease must become more generally recognized.

GLOSSARY

ATROPHY—­A condition of imperfect nutrition producing diminution in size and loss of function of parts.

BERTILLON—­A French anthropologist who devised a system of measurements of the human body for purposes of identification.

BLOOD-PLASMA—­The fluid of the blood.

CELL—­The unit of living matter.  Living things may be unicellular or composed of a multitude of cells which are interdependent.  The general mass of material forming the cell is termed cytoplasm.  In this there is a differentiated area termed nucleus which governs the multiplication of cells.  In the nucleus is a material termed chromatin which bears the factors of heredity.

CHEMOTROPISM—­The influence of chemical substances in directing the movement of organisms.

EXUDATE—­The material which passes from the blood into an injured part and causes the swelling.

FIBRIN—­The gelatinous material formed in the blood when it clots.

HAEMOGLOBIN—­A substance which gives the red color to the blood; by means of its ready combination with the oxygen of the air in the lungs this necessary element is carried to all parts of the body.

INFLAMMATION—­Literally a “burning”; the changes which take place in a part after injury.

LYMPH—­The fluid which is contained in the lymphatic vessels—­nodes.  Circumscribed masses of cells connected with the lymphatic vessels.

OSMOSIS—­The process of diffusion between fluids of different molecular pressures.

SPORE FORMATION—­A mode of reproduction in lower forms of life by which resistant bodies, spores, are formed.  These have many analogies with the seed of higher plants.

SYMBIOSIS—­A mutual adaptation between parasite and host.

TRANSUDATION—­The normal interchange of fluid between the blood and the tissue fluids.  The material interchanged is the transudate.

TROPISM—­The influence of forces which direct the movement of cells.

ULTRA-MICROSCOPE—­A form of microscope which by means of oblique illumination renders visible objects so small as to be invisible with the ordinary microscope.