| 释义 |
decrepitate, v.|dɪˈkrɛpɪteɪt|
[f. med. or mod.L. dēcrepitāre, f. dē- down, away + -crepitāre to crackle, freq. of crepāre to crack. Cf. F. décrépiter (1690 in Hatzf.).]
1. trans. To calcine or roast (a salt or mineral) until it no longer crackles in the fire.
1646Sir T. Browne Pseud. Ep. ii. v. 87 And so will it come to passe in a pot of salt, although decrepitated. 1684Boyle Porousn. Anim. & Solid Bod. viii. 125 A pound of Dantzick Vitriol and a pound of Sea Salt, after the former had been very lightly calcined, and the latter decrepitated. 1799G. Smith Laboratory I. 379 Decrepitate them, i.e. dry them till they crack, in a pan, crucible, or clean fire shovel. 1832G. R. Porter Porcelain & Gl. 82 The salt purified and decrepitated,—that is, subjected to the action of heat until all crackling noise has ceased.
2. intr. Of salts and minerals: To make a crackling noise when suddenly heated, accompanied by a violent disintegration of their particles.
This is owing to the sudden conversion into steam of the water enclosed within the substance, or, as in some natural minerals, to the unequal expansion of the laminæ which compose them. Watts Dict. Chem.
1677Plot Oxfordsh. 54 Put in the fire, it presently decrepitates with no less noise than salt itself. 1800tr. Lagrange's Chem. I. 331 If transparent calcareous spar be exposed to a sudden heat, it decrepitates and loses its transparency. 1849Dana Geol. v. (1850) 324 note, It decrepitates..but does not fuse.
Hence deˈcrepitated ppl. a., deˈcrepitating vbl. n. and ppl. a.
1662R. Mathew Unl. Alch. §101. 165 Let thy salt stand meanly red til it wil crack no more, and that is called decrepitating. 1765Univ. Mag. XXXVII. 84/2, I..take equal parts of decrepitated salt and nitre. 1819H. Busk Vestriad v. 53 Decrepitating salts with fury crack. 1874Grove Contrib. Sc. in Corr. Phys. Forces 304 A brilliant combustion, attended with a decrepitating noise. |