902 ESSENTIAL OILS. 







fully intense odour exciting tears, and produces immediately 

 inflammation and blisters when applied to the skin. Its boiling 

 point is 289.4 (143 centig.). When burned, it produces sul- 

 phurous acid. When the oil and an excess of ammonia are 

 put together in a well stopt phial, the oil in a few days disap- 

 pears, and a mass of beautiful crystals is found in its place, 

 containing the elements of C 8 H 5 NS 2 + NH 3 . This compound is 

 believed by MM. Dumas and Pelouze, who examined it, to 

 belong to the class of amides. Oil of mustard is deprived of 

 all its sulphur by distillation with hydrated oxide of lead, am- 

 monia being formed with sulphuret of lead and another crys- 

 talline substance, sinapoline, C 28 H 24 N 4 O 4 , which also remains 

 in the retort. (Simon). 



To this class of essential oils also belong, oil of horseradish, 

 from Cochlearia armoracia and C. officinalis, oil of garlic, from 

 Allium sativum, oil of onions, from Allium cepa, oil of assafoatida, 

 from Ferula assafcetida, oil of water pepper, Polygonum hydro- 

 piper, of Arum maculatum ; also those of Lepidium latifolium, 

 and of hops, Humulus lupulus. 



The substances which follow are allied to the essential oils. 



Nicotianine, a volatile fatty matter obtained in minute quan- 

 tity by distilling tobacco leaves with water. It is bitter and 

 has a strong smell of tobacco. 



Asarine, from the root of Asarum Europeum, a crystalline 

 substance, fusible in boiling water, volatile, having an aromatic 

 smell and taste resembling camphor. Its composition is 

 expressed by C 16 H n O 4 (Blanchet and Sell.) 



Anemonine from Anemone pulsatilla, netnorosa and prat ensis ; 

 a crystalline substance, C 5 H 2 O 2 (Fehling) ; forms anemonic 

 acid with barytes (Lcewig.) 



Helenine, from Inula helenium ; obtained by distilling the fresh 

 root with water, or by acting on it with hot alcohol. It is crystal- 

 lizable in white prisms, melts at 162, and boils about 530. Its 

 formula is C 14 H 9 O 2 (Dumas), or C 15 H 10 O 2 (Gerhardt.) With 

 nitric acid and chlorine it yields two compounds, nitrohelenine, 

 C i5 H 9 O 2 + NO 4 , and chloride of helenine C 15 H 10 O 2 + C1 2 . With 

 anhydrous phosphoric acid^, helenine yields a hydrocarbon C 15 H 8 . 

 (Gerhardt, Ann. de Chimie, etc. Ixxii, 163.) 



The wood of Quassia amara contains a crystalline body, so 

 also do the pods of Epidendron vanilla, and the seeds of Tan- 



