Motes on scientific research. 131 



The preliminary condition for a more extensive use would be, it is true, that the 

 various essential oils differed in action. Their action, however, has not been studied 

 systematically, so far, and reliable pharmacological information is to be found only in 

 isolated cases; ylang-ylang oil, e.g., has been well examined in this respect 1 ). According 

 to Anselmino, a systematic investigation of the special effect of each of the various 

 essential oils would not promise any great success, as on a whole many of them are 

 rather closely allied in composition. 



The author distinguishes between local and reabsorbing action, which can be brought 

 about by internal administration or inhalation. It can be said in general that all essential 

 oils irritate locally and are poisonous. The quantities given for medicinal purposes 

 or used in order to improve the taste and smell of other substances are so small, 

 however, that no poisonous effect takes place. 



Thujone 2 ) and myristicin 3 ) are looked upon as specifically poisonous, in consequence 

 of reliable investigations. As regards safrole, it is known that, after having been taken 

 internally, it may cause fatty degeneration of the liver and kidneys. 



The bad effect that may be caused by ample inhalation of essential oils is suffi- 

 ciently known; the symptoms, summarized in the term nausea (literally meaning sea- 

 sickness), are numbness, slight giddiness, headache, 8jc., such as are observed after 

 excessive use of scents or prolonged stay in rooms where there are strongly smelling 

 flowers. Geranium oil is looked upon as being specially liable to cause nausea. 



Mustard oils, generally used in alcoholic solution, are known as extraordinarily 

 strong irritants of the skin. The oils of rosemary, thyme, wild thyme, rue, mace, 

 juniper and geranium also irritate the skin. 



The irritative property of essential oils is but little used nowadays in ointments, 

 only the rosemary or nerve ointment still keeps its place, generally speaking. In the 

 veterinary practice and in some popular remedies, turpentine in the form of ointments 

 and plasters still acts a part as irritant, the action of which is chiefly due to its essential oil. 



Oil of turpentine and especially fir oils as well as the oil of Pinus pumilio have 

 found a modern use in medicinal baths, the action of which is due to irritating pro- 

 perties of the essential oils with regard to the skin*). 



According to Anselmino, the irritating effect of tincture of arnica on the skin must 

 likewise be ascribed to the essential oil 5 ). 



Excepting the antiseptic power of some components of the essential oils, the chief 

 aim of their use in dentifrices, tooth-powders, $c. is to modify the taste of these 

 preparations. 



Oil of cloves, when applied against toothaches, does not act only as desinfectant 

 but most probably as a local anaesthetic as well. The other remedies against tooth- 

 ache, such as spirits of mustard and oil of cajuput, act through deflexion or diversion. 

 Anselmino thinks it possible that the cheek rubbed with spirits of mustard burns to 

 such an extent that the toothache is forgotten 6 ). 



The loosening action (oils of turpentine, cypress, eucalyptus and menthol) on the 

 mucous membranes of the nose and the palate and on the respiratory organs consists 



*) P. Kettenhofen, inaugural dissertation, Bonn 1906; Report April 1907, 111. — 2 ) F. Jiirss, Beitrnye zur 

 Wirkuny des Thujons (Contributions regarding the action of thujone). Bericht October 1903, 141. — 3 ) F. Jiirss, 

 Uber Myristicin und einiye ihm nahestehende Substanzen (On myristicin and some allied substances). Bericht April 

 1904, 159. — *) Comp. O. Anselmino and J. Schilling, Therap. Monatsh. 2S (1914), 502. — 6 ) There is scarcely 

 anything known of the composition and properties of arnica flower oil, whereas the oil from the roots has been 

 examined fairly well. The tincture, however, is made from the flowers. — 6 ) According to Schwarz, it would 

 be sufficient to smell mustard oil in order to make the pain cease ! Comp. Report April 1914, 90. 



9* 



