466 H. G. SMITH. 
until all the volatile acid had come over. This had an odour 
of butyric acid strongly marked. The free acid in the 
distillate was exactly neutralised with barium hydrate 
solution, evaporated to dryness and heated in air bath to 
105°C. 
A molecular weight determinations with this barium salt 
gave the following :— 
0°3592 gram gave 0°2668 gram. BaSO, =74°28 per cent. 
Barium butyrate gives theoretically 74°91 per cent. 
BaSO,, so that most probably no other acid than butyric 
was present. The odour and other indications suggested 
the normal form for this acid, and the ethyl ester gave the 
characteristic pine-apple odour. To decide the point the 
calcium salt was prepared by decomposing the remainder of 
the barium salt with sulphuric acid, and distilling over the 
volatile acid. The distillate was exactly neutralised with 
freshly prepared and filtered lime water, using a trace of 
phenolphthalein as indicator. It was then carefully 
evaporated to a small bulk on the water bath until a portion 
of the solid salt separated, but this took up again when the 
liquid cooled. The precipitation was again brought about 
when heated in test tube, but this was also dissolved on 
cooling. It is thus apparent that the acid of this ester 
is normal butyric. 
Determination of the Alcohol. 
On distilling the oil separated after saponification, about 
1°2 per cent. came over below 150° ©. A trace of eucalyptol 
was present and perhaps a trace of pinene also. ‘This 
portion was carefully oxidised with K,Cr,O, + H.,SQO,, by 
heating to boiling, and allowing to stand for twenty-four. 
hours. A volatile acid with the odour of butyric was then 
readily detected, this was distilled over, filtered through 
wet paper, exactly neutralised with barium hydrate solu- 
tion, and evaporated to dryness and heated in air oven. 
