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= Es Bee ay oss ey) NOTES 0} SCIENTIFIC. RESEARCH, ele ‘ 89 
‘even iinet: When the ‘action: was COrsTels the liquid was filtered and a corresponding 
art: of the filtrate used for titration with decinormal iodine solution. — 
“When 0.1 to 0.2 g. of benzaldehyde were shaken with 50 cc. decinormal hydrazine 
; Se iibate solution the interaction manifested itself soon by the formation of a precipitate 
~ and by ensuing separation of the aldazine. After letting the mixture stand for 5, 24 
and 48 hours there were hardly’, any differences to be found on subsequent titration. 
- The average value found. for the benzaldehyde under examination was 99.9 per cent., 
the benzoic ‘acid content amounting to 1.6 per cent. 
4 The valuation of cinnamic aldehyde was carried out in the Same manner, the inter-. 
~action passed off somewhat slower. The cinnamic aldehyde in question, which according 
to the bisulphite process contained 100 per cent. aldehyde, gave on repeated examination 
by. aid of the hydrazine sulphate process values varying between 90 and 93 per cent. 
4 Bs. “On shaking vanillin with decinormal hydrazine sulphate solution the mixture acquires 
_ instantaneously a yellow coloration, the precipitate being formed only after 15 to 20 mi- 
_ nutes’ interaction. The reaction proceeds only very slowly and appears to be completed, 
often only after 24 hours’ standing, as soon as the turbid liquid has turned fully clear, 
although it remains ‘more or less yellow. Since with vanillin the analytical values found 
differed widely, 5 great number of determinations ‘were carried out with this aldehyde, 
_ experiments that the aldehyde content found was the lower the smaller the amount of 
_ aldehyde was ‘which was treated with 50 cc. deeinormal hydrazine sulphate solution. 
p Whereas on examination of _ / 
about 0.3 g. vanillin an averdge of about 90 pe C: aldehyde resulted, 
| there: was found WAN a OP hy ane Hons .tys Bly f 
Se : : BS i, ee 0.1 ” pe eA ae ue ” ay. 80 ,, Tee ate iste 
SS : 3 Weave 0.05 AEN ae rer eri) eats 48 ,, Moen 3 
Be Se ee ” 0.025 CT pe ees | ” ahaa ss Bera Ons Wi ” 
On comparing the amounts of vanillin used and found it appears that the difference 
vin both of these figures with each experiment is fairly constant: — 
ees: t=? Amount analyzed 0.305 g. 0.206 g. 0.104 g.. nee - 0.0250 g. 
, ‘ ditto found . 0.277,, 0.180, 0.083 :,,". 0.026 ,: 0.0015 ,, 
Difference: 0.028 g. 0.026 g. 0.021 g. 0.028 g. 0.0235 g. 
4 The mean mee nee is, therefore, 0.025 g.,7.¢., in each test this amount of vanillin : 
is not found, it being uncertain whether or not this amount is combined with hydrazine. 
_ hydrazine sulphate under the conditions suggested. . 
f= “The vanillin tested showed the m.p. 82 to 83° and on examination according to: 
~ Hanus") method with p-bromophenylhydrazine proved to be, on the average, 100 per cent. : 
It deemed not necessary on account of the results mentioned above to subject 
L autenschlager’s hydrazide method to a trial. test, but at all events we point out that 
v a citronellal the author found 101.3 per cent., whereas, according to our SSE ERE ), 
100, per cent. citronellal is difficult « or even impossible to prepare: 
: R.S. Hiltner®) had worked out a colorimetric method for ee the citral content 
_of lemon extracts and in lemon oils basing on the yellow coloration imparted to a 
dilute alcoholic solution of m-phenylene diamine hydrochloride, at room temperature, 
é 1) Leitschr. Untersuch. d. Nahrungs- u. Genussm. 3 (1900), 657. PLT Report October 1912, 41. — 4) Journ. 
md. eng. Chemistry 1 (1909), 798. Comp. Gildemeister and Hoffmann, The Volatile Oils, 2nd ed., vol. Ill, p. 40. 
SHA 4 , Z 8 
- partly-with vanillin as such, partly with its aqueous solution. It was found in these — ies 
In any case, these experiments proved that vanillin does not react quantitatively with ie 
