32 
from an acetic acid solution have the composition C 19 H 14 0 3 , 
HC1+2C 2 H 4 0 2 , and those from alcohol 2C 10 H 19 O 3 , HC1 
+ 3C 2 H 6 0. 
When sulphuric acid is added to a hot alcoholic solution 
of aurin, small red needles are formed on cooling, which 
consist of (Ci 9 H 14 0 3 ) 2 S0 4 H 2 -f Alcohol. Under the same con- 
ditions an acetic acid solution yields fine prismatic crystals 
or flat, very glistening needles, which are an acid sulphate, 
its formula being Ci 9 Hi 4 0 8 , S0 4 H 2 -f- Acetic acid. 
We have also prepared a nitrate which is readily formed 
and crystallizes well but have not analysed it yet. 
In our first communication to the Chemical Society, we 
described a compound of aurin and sulphur dioxide, which 
is easily obtained in bright red crystals by passing sulphur 
dioxide into a saturated alcoholic solution of aurin. Our 
former observation that this body contains water, but no 
alcohol, we found confirmed; on heating it decomposition 
easily takes place, pure aurin being left behind, but it ap- 
pears to be quite stable when exposed to the air, and even 
on heating it with water no sulphur dioxide is given off, 
but a drop of sulphuric acid added to the mixture is suffici- 
ent to evolve the gas abundantly. Aurin sulphite has the 
composition (Ci 9 H 14 0 3 ) 2 S0 3 H 2 +4H 2 0, 
As we have already showed, aurin forms very character- 
istic compounds with the acid sulphites of the alkali-metals, 
which in accordance with the newly established formula of 
aurin must now be written as follows : 
c 19 h 14 o 3 , so 3 kh 
C 19 H 14 0 3j S0 3 NaH 
C 19 H l4 0 35 S0 3 (NH 4 )H 
We have also found that rosolic acid, or the next higher 
homologue of aurin forms compounds with mineral acids 
which crystallize well. Being therefore a base like aurin, 
we think its name ought to be altered and, as it has only 
been obtained from rosaniline, propose for it the name 
rosaurm. 
