On the Chemical and Natural History of Lupidine, 209 



but this odour does not resemble that of valerianic acid when 

 the oil has not undergone oxidation or contact with air. 



Subjected to distillation, it enters into ebullition at + 140 

 degrees ( = 284° Fahr.), and distils for some time at + 150° 

 ( = 302° Fahr.) to 160 degrees ( = 320° Fahr.), but the tem- 

 perature rises gradually, and when the process is finished, 

 is + 300 degrees ( = 572° Fahr.) 



The portion of this essence obtained between 150° ( = 302° 

 Fahr.) and 160° ( = 320° Fahr.) is a sufficiently thin liquid, 

 slightly amber-coloured, of an odour which does not resemble 

 that of the hop, and of a specific gravity of 0*8887. It has 

 not an acid reaction, but, on exposure to air, it acidifies and 

 becomes resinous ; it is slightly soluble in water, to which 

 it communicates its odour, and the solution exposed to the 

 air acidifies rather readily ; it is soluble in alcohol and in 

 ether. With a cold of -17 degrees ( + 1°4 Fahr.) it lost 

 a little of its fluidity, but its transparency was not altered, 

 even after four or five hours' exposure to that temperature. 

 It deviates to the right the rays of polarized light. Its ro- 

 tatory power (Dextrogyrate) has been found by the red 

 glass to be + 2-7^ for the length of O^^'OSO ; it is then of 



+ ^2-7 



80 xD 



Nitric acid gives at first a beautiful purple colour ; after- 

 wards, if heated a little, the reaction becomes more lively, 

 and the products furnished are a resinous matter and vale- 

 rianic acid. 



Potash in solution fails to attack it at a boiling tempera- 

 ture ; but if we form an emulsion with a concentrated 

 solution of potash, and expose the mixture for some time to 

 contact with air, we find that there are produced valerianate 

 of potash and a resinous matter. 



Fused potassa transforms it into carbonate and valerianate 

 of potassa, with disengagement of hydrogen and of a hydro- 

 carbon liquid. 



This reaction of potassa is very important, because, after 

 some useless trials, and a great number of analyses, it ren- 

 dered clear the true nature of this essence, placing it by the 

 side of the essential oil of valerian. 



