496 ON OUR OIL FLASKS. 



matter attached to the blubber, by which i3 developed a certain fat 

 composed of glycerine and phocenic'acid. Porpoise oil is very like 

 whale oil. Cod-liver oil is got from the livers of the common cod, the 

 dorse, the coal-fish, the burbot, the ling, and the torsk. In Australia, 

 the liver of the dugong is used instead of the cod ; but no dugong 

 liver oil has found its way over here. Fish oil of various kinds i3 

 largely used for soap-making ; and the famous Naples soap is made 

 from fish oil and potash, giving a marvellous lather for strong beards ; 

 but before any soap can be made, the glycerine of the oil must first be 

 got rid of, when the fatty acid is mixed with alkali and soap is formed. 

 In the case of glycerine soap, the glycerine is put back again, when it 

 combines in a different manner. Diachylon plaster, an insoluble soap, 

 is only lead and oil ; and ammonia and oil is a " volatile liniment, 

 forming a milky emulsion, and used as a rubefacient in medicine." Are 

 there many who recognise in these majestic words our old greasy friend, 

 the hartshorn and oil bottle 1 



Then there are essential or volatile oils, found in various parts of 

 plants ; in the flowers of some — as the orange-flower (neroli), the dried 

 clove-bud (essential oil of cloves), the elder-flower, lavender-spikes, 

 rose-leaves (attar or otto of roses), jessamine, mignionette, camomile, 

 and, indeed, in all sweet and strong-smelling flowers ; in the fruit of 

 others — as the oil of bergamot from the ripe fruit of the Citrus berga- 

 mia, the oil of nutmegs (not the butter), extracted from the inner lining 

 of the nutmeg, from juniper-berries, orange rinds, and lemon rinds ; 

 in the bark of others — as oil of cinnamon from the bark of the cinna- 

 mon tree of Ceylon (Laurus cinnamomum), oil of turpentine, distilled 

 from the "oleo resin'' of pine trees, and when rectified and re-distilled 

 sold as the caniphine which smokes so abominably when not sufficiently 

 supplied with air, and which smokes more abominably still when left 

 exposed to the air, by which it becomes resinified again, and unfit for 

 burning ; in the leaves — from orange-leaves, from the dry leaves of the 

 Melaleuca cajeputi, known as cajeput oil from the Moluccas, oil of 

 savine, from the leaves of the Juniperus sabinus, and others ; in the 

 seeds of many, and in the roots of a few. But the essential oils have 

 a less varied usefulness than the fatty ; and if a law was passed pro- 

 hibiting the use of perfumes, there would then be very few distilled at 

 all. But all are not distilled; for the essential oil of certain flowers, in 

 which resides the perfume, or what chemists call the " odoriferous 

 principle," is so delicate and evanescent that the only way to get at it 

 is by imprisoning it in a neutral medium, as in the process called enfleu- 

 rage. Scented buds and petals are gently laid in perfectly inodorous 

 grease, which thus becomes impregnated with the perfume. 



Oil has a peculiar facility for developing heat. If hemp, or wool, or 

 paper, sawdust, rags, soot, shavings — what not of refuse — be smeared 

 with oil, and left to the free action of the sun and air, they will soon 



