151 
while for this substance is given e.g. 203°; a titration of the acid 
with + N. KOH and phenolphtalein as indicator gave the per- 
centage 99,8. 
The melting-point of the cinnamic-acid that was present in the 
laboratory was 133°, of the ortho-coumaric-acid 205°. The «-naph- 
toic-acid and the a-oxy-naphtoïc-acid melted respectively at 159° 
and at 187°. 
It was found, that in diluted alcoholic solutions these compounds 
practically did not hinder the inversion of cane sugar (Table 1); 
Table IV refers to the naphtoïc-acid. From the tables II and III 
we see, that in alkalic solution the behaviour of ortho-phtalic-acid 
is dibasic, of «-naphtoïc-acid monobasic, of cinnamic-acid monobasic 
and finally of coumaric-acid dibasic. : 
This might have been expected from the above given structural 
formulae. 
We further investigated: a-naphtol (M.W. 144, melting-point 96°), 
B-naphtol (M.W. 144, melting-point 122°), 2.3. oxy-naphtoic-acid 
(melting-point 217°) $ 
ANN on 
\/_/ COOH 
and B-naphtoic-acid (melting-point 165°, M.W. 172). 
From the experiments made with a nearly 50 °/,-alcoholic solution 
we learned, that «- and g-naphtol, «-naphtoic-acid and 2.3. oxy- 
naphtoic-acid practically do not influence the inversion of cane sugar 
by hydrochloric-acid (Table IV). 
The behaviour of «- and g-naphtol in alkalic solution was approxi- 
mately monobasic just as of 8-naphtoic-acid ; the 2.3. ovynaphtoic-acid 
behaved in an alkalic medium as a monobasic acid; this was also 
the case with the 1.2. oxynaphtoic-acid (Tables V and VI). 
In the same way as has been done for the salicylic-acid, 
led by analogous experiments), we are now inclined to assume 
also for the mentioned oxynaphtoic-acids, at least in alkalic media, 
a “ketoformula’, e.g. as follows : 
M.W. = 188 
O 
| 
EE C 
EET Rs) VV ZH 
ee ER ENZ 
2. 3. oxynaphtoic-acid 1. 2. oxynaphtoic-acid 
(ketoformula) (ketoformula) 
_1) H. I. Waterman, These Proc, XX, 581 (1917). 
