ON THE COMPOSITION OP BIRD-LIME. 23 



with acetic acid to neutral reaction, again \Yash, dry, dissolve in hot 

 90% spirit, cool, and crystallise out from the solution the bird-lime 

 alcoliol. This method we have not found to work well, because of 

 the great difficulty in washing properly the voluminous gelatinous 

 precipitate, and in just neutralising it with acetic acid. This precipi- 

 tate contains, besides the alcohols and resinoïd body, much acid 

 potassium palmitate, to which indeed its bulky state is partly due, 

 and we have found it far preferable to convert the potassium palmitate 

 either into the calcium salt or into free acid, as jibove described. 

 Personne seems not to have recognised the presence of any fatty salt 

 in the precipitate of the alcohols. 



Separation of the alcohols from each other, and their petrification. — 

 The crude solid alcohols can only be fully separated from each other 

 by fractionated extraction with strong spirit, repeated until products 

 are obtained of constant melting-point. The alcohols, already treated, 

 as described, with SO "/<> spirit to remove the resinoïd body, are 

 warmed with successive portions of spirit increasing in strength 

 from about 85 ^o to over 90 ''/o, each portion of the solvent deposit- 

 ing crystals of the alcohols as it cools, and each mother-liquor, by 

 successive evaporations, yielding a series of other crystalline deposits, 

 all similar in appearance. When the last mother-liquors are too 

 small in quantity and too impure to yield a satisfactory product by 

 further evaporation, they are rejected or worked up for the little 

 resinoïd body they contain. The portions of the alcohols least 

 soluble in spirit consist principally of the one alcohol, and those most 

 soluble, of the other alcohol. The intermediate portions yield by re- 

 newals of the treatment with spirit other series of deposits of higher 

 and lower degrees of solubility, the extremes of which are the two 

 alcohols nearly free of each other. The portions of the less soluble 

 alcohol are submitted to further fractionation, until the part undis- 



