— 117 — 



phthaleine solution (1:100) and the acid estimated by titrating with semi- 

 normal potash liquor 1 ). Next, the contents of two of the flasks, with an 

 addition of 10 cc. seminormal potash liquor are saponified during 1 hour 

 on the water-bath by the familiar method. The contents of the third flask 

 are boiled for 2 hours with 20 cc. liquor and those of the fourth flask are 

 diluted with 25 cc. neutral 96% alcohol and saponified during 1 hour 

 with 10 cc. liquor. At the end of the boiling the four samples should 

 be cooled down quickly and equally by immersion into cold water and 

 titrated immediately. 



In the case of pure bergamot and lavender oils the difference in 

 the ester values between the two-hours' and the one-hour's diluted sample 

 amounted to 3, or at most 4, whereas the ester values of the two 

 normal saponifications represented about the mean of these figures. If 

 terpinyl acetate is added to the oil the difference becomes correspondingly 

 greater, the ester value of the two-hours' saponification being increased 

 in proportion to the contents, whereas that of the sample diluted with 

 alcohol only increases slightly. The ester value of the two normal 

 saponifications always remains at about the mean of the two others. The 

 subjoined table shows the values found by us for a pure bergamot oil 

 and for the same oil after adding the stated quantities of terpinyl acetate: 



Seminormal Potash liquor: 



10 cc. 



20 cc. 



10cc.+ 

 25 cc. ale. 



Difference 

 between 



Time of saponification: 



1 hour 



2 hours 



1 hour 



Cols. 2 and 3 



Bergamot oil, pure . . . 



99,7 



100,5 



97,4 



3,1 



+ 2°/o Terpinyl acetate 



102,1 



104,5 



98,1 



6,4 



+ 4°/o „ 



103,3 



108,1 



98,1 



10,0 



+ 6% „ 



105,7 



112,2 



98,6 



13,6 



+ 8% „ 



107,0 



114,4 



98,4 



16,0 



+ 10% „ 



108,6 



118,1 



99,1 



19,0 



+ 15% n 



113,4 



126,7 



101,0 



25,7 



+ 20% „ 



118,0 



135,6 



101,3 



34,3 



it follows from the above that an addition of 10% terpinyl acetate 

 produces a difference in the ester values of 19 (5,5 according to the 



i) Report April 1911, 69. 



