| Bernoulli's law | <physics> When friction is negligible, the velocity of flow of a gas or fluid through a tube is inversely related to its pressure against the side of the tube; i.e., velocity is greatest and pressure lowest at a point of constriction. Synonym: Bernoulli's principle, Bernoulli's theorem. (05 Mar 2000) |
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| Berthollet's law | Salts in solution will always react with each other so as to form a less soluble salt, if possible. (05 Mar 2000) |
| biogenetic law | The theory that ontogeny recapitulates phylogeny, which means that one can trace the evolutionary development of a species by studying the development of an individual embryo or young of that species. The theory is still used, especially in paleontology, but has been found to not be strictly true when applied to problems in biology. (09 Oct 1997) |
| biot-savart law | <physics> General formula for determining the magnetic field due to a steady line (not space) current. Related to Ampere's Law. (19 Jan 1998) |
| Blagden's law | The depression of the freezing point of dilute solutions is proportional to the amount of the dissolved substance. (05 Mar 2000) |
| Bowditch's law | Consistently total response to any effective stimulus. Synonym: all or none law. (05 Mar 2000) |
| boyle's law | This law states that the volume of a sample of gas is, at a constant temperature, inversely proportional to the pressure of that gas. (09 Oct 1997) |
| Broadbent's law | Lesions of the upper segment of the motor tract cause less marked paralysis of muscles that habitually produce bilateral movements than of those that commonly act independently of the opposite side. (05 Mar 2000) |
| Bunsen-Roscoe law | In two photochemical reactions, e.g., the darkening of a photographic plate or film, if the product of the intensity of illumination and the time of exposure are equal, the quantities of chemical material undergoing change will be equal; the retina for short periods of exposure obeys this law. Synonym: reciprocity law, Roscoe-Bunsen law. (05 Mar 2000) |
| by-law | 1. A local or subordinate law; a private law or regulation made by a corporation for its own government. "There was likewise a law to restrain the by-laws, or ordinances of corporations." (Bacon) "The law or institution; to which are added two by-laws, as a comment upon the general law." (Addison) 2. A law that is less important than a general law or constitutional provision, and subsidiary to it; a rule relating to a matter of detail; as, civic societies often adopt a constitution and by-laws for the government of their members. In this sense the word has probably been influenced by by, meaning secondary or aside. Origin: Cf.Sw.bylag, D.bylov, Icel.barlog, fr.Sw.& Dan. By town, Icel. Baer, byr (fr. Bua to dwell) + the word for law; hence, a law for one town, a special law. Cf.Birlaw and see Law. Source: Websters Dictionary (01 Mar 1998) |
| Galton's law | In a population mating at random, the progeny of a parent with an extreme value for a measurable phenotype will tend on average to have values nearer the population mean than in the extreme parent. See: law of regression to mean. Synonym: law of regression to mean. (05 Mar 2000) |
| Magendie's law | The ventral spinal roots are motor, the dorsal are sensory. Synonym: Bell-Magendie law, Magendie's law. (05 Mar 2000) |
| van der Kolk's law | In a mixed nerve, the sensory fibres are distributed to the parts moved by the muscles controlled by the motor fibres. (05 Mar 2000) |
| van't Hoff's law | In stereochemistry, all optically active substances have one or more multivalent atoms united to four different atoms or radicals so as to form in space an unsymmetrical arrangement, the osmotic pressure exerted by any substance in very dilute solution is the same that it would exert if present as gas in the same volume as that of the solution; or, at constant temperature, the osmotic pressure of dilute solutions is proportional to the concentration (number of molecules) of the dissolved substance; i.e., the osmotic pressure, π, in dilute solutions is π = RTσci, where R is the universal gas constant, T is the absolute temperature, and ci is the molar concentration of solute i, the rate of chemical reactions increases between two-and three-fold for each 10캜 rise in temperature. (05 Mar 2000) |
| Gay-Lussac's law | All gases expand equally on heating, namely, 1/273.16 of their volume at 0캜 for every degree Celsius. Synonym: Gay-Lussac's law. (05 Mar 2000) |