77 
of Edinburgh, Session 1869 - 70 . 
possible that mere pressure would decompose these oxides, at least 
in part, into metal and the higher oxide. The instability of a 
body of this type, such as sub-oxide of mercury, is well known, 
mere titration effecting the liberation of metal with formation of 
the higher oxide. In this way, therefore, it seems to support the 
argument adduced. 
2. Note on Inverted Sugar. By James Dewar, Lecturer on 
Chemistry, Veterinary College, Edinburgh. 
For some time past an animated discussion has been going on in 
the columns of the “ Comptes Rendus de I’Academie des Sciences” 
between MM. Dubranfaut and Maumene regarding the nature of in¬ 
verted sugar. M. Dubranfaut, many years ago, made many valuable 
additions to our knowledge concerning the composition and reac¬ 
tions of various sugars, especially in explaining the result of the 
action of dilute acids on cane sugar. He explained the levo-rotatory 
action of inverted sugar, and its rapidly varying power with the 
temperature, as the result of a molecule of water in reacting with 
a molecule of cane sugar, generating one molecule of glucose and 
one of lmvulose. Dubranfaut believed that inverted sugar consisted 
of a mixture of glucose and lsevulose in equal weights; and although 
he did not make a direct analysis of the product, yet he was justly 
entitled to assume that it was so constituted, seeing that, generally, 
it agreed with a mean of the properties of inulin sugar and dex¬ 
trose. 
In order to support the above view, he separated levo-glucose 
from the inverted sugar, through the insolubility of the lime com¬ 
pound, and compared its properties with pure lmvulose. The de¬ 
composition would, according to Dubranfaut, be as follows :— 
+ 
C 12 H 29 O n + HD 
+ 73-8 
C S H 2 0 6 + rn.u 
+ 56 -106 
(-25) 
So thoroughly had his facts and explanations been accepted by 
chemists generally, that, up till a recent date, no one discovered 
any flaw in his researches, and therefore no doubt was thrown on 
the validity of this theory. Recently, Maumene has reinvestigated 
'VOL. VII. 
