Aniline, Chro′mates of. Prep. 1. (NEUTRAL CHROMATE.) From sulphate or oxalate of aniline and chromate of potash, by double decomposition.
2. (BICHRO′MATE:—Mr W. H. Perkin.) Sulphate of aniline and bichromate of potash, in equivalent quantities, are separately dissolved in water, and the solutions, after being mixed, are allowed to stand for several hours. The whole is then thrown upon a filter, and the black precipitate which forms is washed and dried. It is next digested in coal-tar naphtha (—? benzol), to extract a brown resinous substance; after which it is digested in alcohol, to dissolve out the colouring matter (BICHROMATE OF ANILINE), which is left behind on distilling off the spirit, as a coppery friable mass. Patented.
Aniline, Cy′anide of. Benzonitrile.
Aniline, Ox′alate of. (C6H7N)2C2O4. Obtained by saturating an alcoholic solution of oxalic acid with aniline; the salt separating as a crystalline mass. It is very soluble in hot water; much less so in cold water; only slightly soluble in alcohol; and insoluble in ether. It may be crystallised from hot water or boiling alcohol. Used chiefly to form other salts.
Aniline, Sul′phate of. (C6H7N)2SO4. Prepared by saturating aniline with dilute sulphuric acid, and gently evaporating the liquid until the salt separates. By re-solution in boiling alcohol, it crystallises out, as the liquor cools, under the form of very beautiful colourless plates, of a silvery lustre. It is freely soluble in water, and in hot alcohol; scarcely soluble in cold alcohol; and insoluble in ether.
It is chiefly employed in the preparation of the new aniline dyes.
ANIMAL′CULE (-kūle). [Eng., Fr.; pl. animal′cules.] Syn. Animal′culum (pl., animal′cula[66]), L.; Thierchen, Ger. In zoology and physiology, a microscopic animal, or one so extremely small, that it is either invisible, or not distinctly discernible, without the aid of a lens or microscope; more especially one that is not perceptible to the naked eye. “A mite was anciently thought the limit of littleness; but there are animals 27,000,000 of times smaller than a mite.” A thousand millions of some of the animalcula found in common water are said to be collectively of less bulk than a single grain of sand; yet their numbers are so prodigious as sometimes to give the fluid they inhabit a pale red or yellow tinge. The milt of a single codfish is said to contain more of these minute animals than there are people in the whole earth. Animalcula were first scientifically observed by Leuwenhoek about the year 1677. Assisted by the microscope he unveiled, as it were, he created a new world for future naturalists and microscopists to explore.
[66] Animalculæ for the plural, sometimes heard and met with, is a barbarism; yet one not wholly confined to the vulgar, for we find it in Vincent’s edition of Haydn’s admirable ‘Dict. of Dates,’ not merely twice, or oftener, in the text, but as a ‘title-word,’ and also in some other works where we might least expect it.
“Take any drop of water,” says Professor Rymer Jones, “from our rivers, from our lakes, or from the vast ocean itself, and place it under the microscope; you will find therein countless living beings moving therein in all directions with considerable swiftness, apparently gifted with sagacity, for they readily elude each other in the active dance they keep up.... Increase the power of your glasses, and you will soon perceive inhabiting the same drop, other animals compared to which the former were elephantine in their dimensions, equally vivacious and equally gifted. Exhaust the art of the optician, strain your eyes to the utmost, until the aching sense refuses to perceive the little quivering movement that indicates the presence of life, and you will find that you have not exhausted nature in the descending scale.”
Amongst the most remarkable discoveries of modern science must be reckoned that of fossil animalcules in such abundance as to form the principal part of extensive strata. This discovery is due to Ehrenberg, who found the Polierschiefer (the polishing slate or tripoli) of Bilin to be almost entirely made up of the siliceous shields of a minute fossil animalcule, the length of one of which is about 1⁄288th of a line, so that about 23,000,000 of animalcules must have gone to form a cubic line, and 41,000,000,000 to form a cubic inch of the rock. Ehrenberg succeeded in discovering the formation of similar strata in deposits of mud at the bottom of lakes and marshes, the mud swarming with living animalcules, probably in their turn to be fossilised. The bergmehl, or mountain meal of Sweden and other parts of Europe, which is sometimes used as an article of food, is entirely composed of the remains of animalcules; not merely, however, of their siliceous shields, for it contains a considerable per-centage of dry animal matter. Some animalcules prefer waters impregnated with iron, and their death gives rise to an ochreous substance in which iron is a principal ingredient.