— 51 - 



sodium acetate does not play the part of a dehydrating agent, which 

 Umney and Parry would fain assign to it. 



The authors in question also take umbrage at our entire agreement 

 with Kleber's suggestion that for the sake of clearness fused sodium 

 acetate should be prescribed for the acetylation, and they attempt to fight 

 us with our own weapons by pointing out that we ourselves have always 

 recommended dry sodium acetate for this purpose, and that this same 

 substance is mentioned both in the first and in the second edition of our 

 book The Volatile Oils. We admit this at once, but with the best will in 

 the world we cannot see that this is inconsistent with our regarding 

 Kleber's recommendation as fully justified; for although to the chemist 

 "dry sodium acetate" may mean the anhydrous salt, we are of opinion 

 that there is no harm whatever in expressing oneself somewhat more 

 clearly and using the term "fused sodium acetate", particularly so since 

 it has been shown that the term "dry" sodium acetate has been mis- 

 understood by American chemists 1 ). 



We simply do not understand why Messrs. Parry and Umney should 

 look upon Kleber's proposal as if it were so to say a personal insult. In 

 any case we trust they will conclude from our admission that we are 

 always very ready to make concessions when they appear to us to be 

 to the purpose. It was obedience to this principle which caused us at 

 the time (Report April 1910, 154) to advocate the two hours' acetylation 

 of citronella oils after de Jong had drawn attention to the fact that an 

 acetylation of one hour gave too low values. 



Fault has also been found with us because we have not adversely 

 criticised Kleber's suggestions relating to the washing-out of the acetylation- 

 mixture, and in this connection also Parry endeavours to convict us of 

 contradictory views by quoting passages from our above-mentioned book. 

 Parry, however, has altogether overlooked the fact that when reproducing 

 Kleber's recommendation in our last Report (p. 36), we referred in a foot- 

 note to our book, with the intention — needless to say — of showing that 

 we ourselves do wash out the acetylation-mixture. As it is possible to 

 do this by different methods without thereby altering the acetylation- 

 prescription itself in any way, and without giving rise to errors, there 

 was no reason whatsoever why we should disparage Kleber's method. 



But the suggestion made by the English chemists that the acetylated 

 oil should only be saponified for the space of half an hour is a very 

 different matter. We certainly do protest against such a modification, 

 and that on the ground of experiments carried out by us with mixtures 

 of known geraniol- and citronellal-content, which showed that half an 

 hour's heating with semi-normal-potash liquor is not sufficient for pur- 

 poses of quantitative saponification. We did not specially mention this 



!) Kleber, ibidem 229. 



4* 



