SPIKEXAED AXD VALEPJAX. 283 



first process, viz., the sodium salt is decomposed by very dilute 

 sulphuric acid, and the monohydrated valerianic acid rectified out 

 by cautious distillation. 



The process of oxidation of amyl alcohol has also been described 

 as follows : — One part of amyl alcohol (potato oil) mixed with two 

 parts of strong sulphuric acid is allowed to How slowly into a 

 solution of five parts potassium clichromate in w^ater, and when 

 the first action, which takes place spontaneously, is over, the 

 mixture is heated for some time in a flask provided with a vertical 

 condenser, in order to convert the Valcral (valerianic aldehyde) 

 produced in the first instance, into valerianic acid. The vapours 

 are then allowed to distil over and condense in an ordinary 

 condenser. The distillate is saturated with sodium carbonate ; the 

 amyl valerianate contained in it is distilled off, and the dry residue 

 of sodium valerianate is dissolved in an equal weight of water and 

 distilled with sulphuric acid {h to -i part of sulphuric acid to one 

 part of sodium salt). The distillate consists of an aqueous 

 solution of valerianic acid, surmounted by an oily layer consisting 

 of a definite hydrate C. H;^^ 0^, H^ 0, from wdiich the pure 

 monohydrate, C^H^qOo, may be obtained by rectification. A 

 milky aqueous distillate passes over at first, and afterwards, at 

 175^ C. the pure acid in the form of an oily liquid. 



Although oil of Valeriana officinalis, and many compounds 

 obtainable from it are offensive in odour, some of the compounds 

 of valerianic acid are highly fragrant, such as: — Aviyl valerianate 

 Q. H-^-^ C. H;, Oo, a colourless volatile liquid wdiich when diluted 

 with 5 or 6 volumes of alcohol and other ingredients, forms the 

 Apple essence used for flavouring. 



Amyl valerianate is abundantly formed during the preparation 

 of valerianic acid from potato oil, and is recognised by the offensive 

 odour of rotten apples evolved during the process. By treating 

 the crude product of the distillation wdth a w^eak solution of pure 

 potash, the valerianic acid is removed and the amyl valerianate 

 obtained nearly pure. It can also be obtained by the direct 

 action of valerianic acid on fusel oil. Its fragrance, as above 

 observed, is developed by dilution with alcohol, but in the pure 

 state it is rank. Care should be taken to employ pure potato oil, 

 thoroughly rectified of all impurities, as some impurities (usually 

 present) would be apt to form by oxidation butyric and propionic 



