Obs. Bandoline is used by ladies and by hairdressers for stiffening the hair, and to make it curl firmly and remain in place. It is applied either by moistening the fingers and passing the hair through them, or by means of a small sponge. See Pommade.
FIXED AIR. See Carbonic Acid.
FIXED OILS. See Fat and Oils.
FLAKE WHITE. See White Pigments.
FLAME. Gas or vapour in an incandescent state. The light emitted from pure flame is exceedingly feeble; illuminating power being almost entirely dependent upon the presence of solid matter. See Illumination, and below.
Flame Colours. The vapours of metallic compounds communicate colours to flames. The characteristic colours of some metals are very beautiful, and their exhibition forms a favorite experiment of chemical lecturers. The coloured flames are generally produced by the combustion of alcohol or rectified spirit upon certain salts in fine powder. In this way a GREEN colour is communicated by boracic acid or chloride of copper; a RED one by the nitrates of iron, lime, or strontia; a VIOLET, by potassa and its salts; and a YELLOW, by nitrate of soda. Messrs Church and Crookes have recently described a mode of exhibiting the characteristic flames of the metals which is admirably adapted for the lecture-table.[312] ‘Gun-paper,’ made in the same way as ‘gun-cotton,’ is to be soaked in solutions of the chlorates of the different metals, dried with care, and kept dry. A good ‘gun-paper’ for the purpose is prepared by soaking strips of Swedish filtering-paper for ten minutes in a mixture of 4 parts oil of vitriol with 5 parts strong nitric acid, both by measure. The strips, when taken out of the acid, should be washed first with cold, and then with hot rain or distilled water, till the washings are no longer sour to the taste. The solutions of the metallic salts need not be very strong; but if they are warm, the strips of ‘gun-paper’ will be more easily and completely saturated with them. Since some of the chlorates attract moisture from the air, it is better to dry the papers prepared with them before the fire previous to lighting them. They are shown to best advantage when a strip is loosely crumpled up into a pellet, lighted quickly at one corner, and thrown up into the air against a dark back ground. They leave after burning, if properly prepared, no ash whatever. Paper prepared with the salt of potassa gives a flash of VIOLET flame, that prepared with the soda salt the characteristic YELLOW flame, and that with chlorate of baryta a very beautiful GREEN light. The chlorates of strontium, lithium, and calcium, when thus ignited, give intense colours. The VIOLET-BLUE flame of copper is well seen, even with the chloride of that metal, while paper soaked in nitrate of potassa shows the potassium flame better than if the chlorate be used. ‘Gun-paper’ prepared with a very weak solution of chloride or chlorate of thallium shows the characteristic SPRIG-GREEN flame of that metal with great distinctness. Chlorate of barium, being an article of commerce, may be employed for the preparation of the other chlorates, it being merely necessary to add to this salt in solution an exactly equivalent quantity of the sulphate or carbonate of the metal whose chlorate is desired. For instance, in order to make ‘chlorate of copper,’ 15·1 gr. of chlorate of barium being dissolved in hot distilled water, a boiling solution containing 12·5 gr. of pure crystallised sulphate of copper is to be added to it. Insoluble white ‘sulphate of baryta’ falls, while the solution, filtered and evaporated, yields the new chlorate in crystals. See Fires, Pyrotechny, &c.
[312] See ‘Intellectual Observer,’ April, 1863.
FLAN′NEL. It has been shown by the experiments of Count Rumford that the conducting power of the different materials employed for clothing varies considerably. A thermometer surrounded with cotton wool, and heated by immersion in boiling water, took 1046 seconds to lose 135° Fahr., when plunged into a bath of melting ice; but, under the same circumstances, when sheep’s wool was employed, 1118 seconds elapsed before a like sinking of the thermometer took place (‘Phil. Trans.,’ 1792); thus showing the greater conducting power of the former, and consequently the superiority of the latter substance for the manufacture of warm clothing. But the chief advantage of wool, as an article of underclothing, depends less upon its actual power of conducting heat than its peculiar texture. Flannel acts as a gentle stimulus on the skin, and exercises the most beneficial action, by keeping the pores clean, and in a state most favorable to perspiration. This action is a species of friction similar in character, although inferior in degree, to that of the common flesh-brush or horse-hair glove, so long employed as a skin stimulant. Flannel has also the advantage
of absorbing the perspiration as soon as emitted, and allowing its watery portion to pass off into the atmosphere almost as soon as formed, but this is not the case with cotton and linen fabrics. The different effects of flannel and linen are particularly susceptible during brisk exercise. When the body is covered with the former, though perspiration be necessarily increased, the perspired matter freely passes off through the flannel, and the skin remains dry and warm. If the same exercise be taken in linen shirts, perspiration, as in the former case, is indeed also increased, but the perspired matter, instead of being dispersed into the atmosphere, remains upon the linen, and not only clogs the pores of the skin, but gives a disagreeable sensation. From this property of flannel, persons who wear it next the skin seldom catch cold from changes of temperature, even though perspiring profusely; but in similar cases, when linen or calico shirts are worn, chilliness immediately comes on, followed by sniffling, sneezing, and cough, and all the other symptoms of severe catarrh.
The common objections raised against the use of flannel are founded on vulgar prejudices, ignorance, obstinacy, or bravado, and are undeserving of the notice of sensible people. In a fickle and moist climate like that of England, every person should wear a robe of flannel next the skin, or at all events a waistcoat of flannel reaching below the loins; and this should not be discarded as soon as the cold weather has passed, but its use should be continued all the year round; for in reality flannel is, if possible, even more required in summer than in winter, because persons perspire more freely in hot than in cold weather, and are consequently more susceptible of cold, while at that period of the year their clothing is less capable of protecting them from the effects of sudden changes of temperature and draughts of cold air, moisture, &c. Females, children, persons of delicate constitutions, and all others who from their habits of body or life perspire freely, or are much exposed, should wear flannel.