PHARMACY. 



CLASS VIII. Olea Volatilia. VOLATILE 

 OILS. 



These are prepared nearly in the same 

 manner as distilled waters, except that 

 less water is to be added. 



Seeds, and woody substances, are to be 

 previously bruised, or rasped. The oil 

 comes over with the water, and is after- 

 wards to be separated from it, according 

 .as it may be lighter than the water, and 

 swim upon its surface, or heavier, and 

 sink to the bottom. 



Besides, in preparing distilled waters 

 and oils, it is to be observed, that the 

 goodness of the subject, its texture, the 

 season of the year, and similar causes, 

 must give rise to so many differences, 

 that no certain or general rule can be 

 given to suit accurately each example. 

 Hence, the following is the mode pre- 

 scribed by the London College. 



According to these 'directions are pre- 

 pared the volatile, distilled, or essential, 

 oils ; or olea volatilia, Edin. distilla, Dub. 

 vel essentialia, Lond. 



Anise, pimpinellas anisi, Edin. anisi, 

 Lon. Dub. 



Caraway, carui, Lond. Dub. 



Fennel seeds, seminum foeniculi dulcis. 

 Dub. from the seeds. 



Juniper berries, juniper! communis, 

 Edin. baccarum juniperi, Dub. juniper! 

 baccae, Lond. from the berries. 



Pimento, myrti pimentae, Edin. from 

 the fruit. 



Fennel flowers, florum fcrniculi dulcis, 

 Dub. 



Rosemary, rorismarini officinalis,Edin. 

 rorismarini, Lond. Dub. 



Lavender, lavandulae spicae, Edin. la- 

 vendulae, Lond. 



Peppermint, menthae piperitse, Edin. 

 menthae piperitidis, Lond. Dub. 



Spearmint, menthae sativae, Lond. Dub. 



Pennyroyal, pulegii, Lond. Dub. 



Origanum, origani, Lond. Dub. 



Rue, rutae, Dub. 



Savine, juniperi sabinae. Edin. sabinx. 

 Dub. from the flower, or herb in flower. 



Sassafras, lauri sassafras, Edin. sassafras, 

 Lond. from the root. 



And, turpentine, pinus picea, from the 

 resin . 



The residuum, after the oil has been 

 extracted, is the officinal resin (resina 

 flava) : and a rectified spirit is obtained by 

 distilling the oil of turpentine with four 

 times its weight of water. 



The spirit of turpentine, as this essen- 

 tial oil has been styled, is frequently taken 



internally as a diuretic and sudorific; and 

 it has sometimes a considerable effect 

 when taken to the extent of a few drops 

 only. It has, however, been given in 

 much larger doses, especially when mixed 

 with honey. Recourse has principally 

 been had to such doses in cases of chronic 

 rheumatism, particularly in those modifi- 

 cations of it which are termed sciatica 

 and lumbago; but sometimes it induces 

 bloody urine. 



The water employed in the distillation 

 of volatile oils always imbibes some por- 

 tion of the oil; as is evident from the 

 smell, taste, and colour, which it acquires. 

 It cannot, however, retain above a certain 

 quantity; and, therefore, such as has been 

 already used and almost saturated itself, 

 may be advantageously employed, instead 

 of common water, in a second, third, or 

 any future distillation of the same subject. 



After the distillation of one oil, particu- 

 lar care should be had to clean the worm 

 perfectly before it be employed in the 

 distillation of a different substance. Some 

 oils, those of wormwood and aniseeds for 

 instance, adhere to it so tenaciously, as 

 not to be melted out. by heat, or washed 

 off by water; the best way of removing 

 these, is to run a little spirit of wine 

 through it. 



Volatile oils, after they are distilled, 

 should be suffered to stand for some days, 

 in vessels loosely covered with paper, 

 till they have lost their disagreeable fiery 

 odour, and become limpid; then put 

 them up in small bottles, which are to be 

 kept quite full, closely stopped, in a cool 

 place. With these cautions, they will 

 retain their virtues in perfection for many 

 years. 



Most of the oils mentioned above, are 

 prepared by our chemists in Britain, and 

 are easily procurable in a tolerable de- 

 gree of perfection; but the oils from the 

 more expensive spiceries, though still 

 introduced among the preparations in the 

 foreign pharmacopoeias, are, when em- 

 ployed among us, usually imported from 

 abroad. 



These are frequently so much adulte- 

 rated that it is not easy to meet with such 

 as are at all fit for use. Nor are these 

 adulterations easily discoverable. The 

 grosser abuses, indeed, may be readily 

 detected. Thus, if the oil be mixed with 

 spirit of wine it will turn milljy on the 

 addition of water; if with expressed oils, 

 rectified spirit will dissolve the volatile, 

 and leave the other behind ; if with oil of 

 turpentine, on dipping a piece of paper 



