n. [ Micro- + Gr. &unr_; an earthquake, fr. &unr_; to shake. ] A feeble earth tremor not directly perceptible, but detected only by means of specially constructed apparatus. -- Mi`cro*seis"mic Mi`cro*seis"mic*al a. [ Webster 1913 Suppl. ]

n. [ Microseiem + -graph. ] A microseismometer; specif., a microseismometer producing a graphic record. [ Webster 1913 Suppl. ]

n. [ Microseiem + -logy. ] Science or study of microseisms. [ Webster 1913 Suppl. ]

n. [ Microseism + -meter. ] A seismometer for measuring amplitudes or periods, or both, of microseisms. -- Mi`cro*seis*mom"e*try n. [Webster 1913 Suppl.]

a. [ Micro- + Gr. &unr_; sign, mark: cf. F. microsème. ] (Anat.) Having the orbital index relatively small; having the orbits broad transversely; -- opposed to megaseme. [ 1913 Webster ]

v. t. & i. (Med.) To affect with necrosis; to undergo necrosis. Quain. [ 1913 Webster ]

a. (Med.) Affected by necrosis; dead; as, a necrosed bone. Dunglison. [ 1913 Webster ]

n. [ F. sucre sugar. See Sugar. ] (Chem.) A common variety of sugar found in the juices of many plants, as the sugar cane, sorghum, sugar maple, beet root, etc. It is extracted as a sweet, white crystalline substance which is valuable as a food product, and, being antiputrescent, is largely used in the preservation of fruit. Called also saccharose, cane sugar, etc. At one time the term was used by extension, for any one of the class of isomeric substances (as lactose, maltose, etc.) of which sucrose proper is the type; however this usage is now archaic. [ 1913 Webster +PJC ]

☞ Sucrose proper is a dextrorotatory carbohydrate, C12H22O11. It does not reduce Fehling's solution, and though not directly fermentable, yet on standing with yeast it is changed by the diastase present to invert sugar (dextrose and levulose), which then breaks down to alcohol and carbon dioxide. It is also decomposed to invert sugar by heating with acids, whence it is also called a disaccharate. Sucrose possesses at once the properties of an alcohol and a ketone, and also forms compounds (called sucrates) analogous to salts. Cf. Sugar. [ 1913 Webster ]