220 
The influence of glycerol is certainly in harmony with these views. 
As we have stated this influence is very slight; two of the OH-groups 
are therefore, most likely, not situated so favourably as in pyrocatechol. 
But still they are not situated so unfavourably as in the simple 
elycols and this cannot be otherwise, for even when the three OH- - 
groups repel each other as far as possible the situation of these 
groups viewed two by two must still be more favourable than in 
the said bivalent alcohols. | 
The fact that on the other hand the position of the hydroxyl groups 
in pyrocatechol and in dioxynaphtalene is so particularly favourable 
must be attributed to the ring-system of the benzene, which forces 
them to remain in the plane of the ring and at the same, or outer, side. : 
The fact that, according to MaGnaninir’s measurements, the «-OXy- 
acids and salicylic acid affect the conductivity of boric acid positively, 
points to a position of the hydroxyl groups, in regard to each other, 
which is more favourable than in the glycols. This is very com- 
prehensible when we consider that the OH-group of the a-carbon 
atom finds at the other side of the acid OH-group of the carboxyl 
group an oxygen atom, and not the hydrogen atoms of the glycols. 
If the number of hydroxyl groups in saturated compounds is greater 
than two, it is obvious that the chances of a favourable position 
increase and in harmony therewith we find that erythro] exerts a 
stronger influence on the conductivity of boric acid than glycerol 
and that the action of mannitol and dulcitol is more important still. 
For '/, mol. of the alcohols on */, mol. of boric acid was found: 
K x 1052 = 
Glycerol | Erythrol | Mannitol | Dulcitol 
8.7 | ead | 685 | 717 
| 
In the case of these saturated polyalcohols it is, at the present, 
still somewhat difficult to point out the most probable position of 
the hydroxyl groups by means of a determination of the influence 
exerted on the conductivity. 
This is much more easy in the case of cyclic systems where the 
mobility of the molecule has been lessened to a considerable extent 
by the closing of the ring thus causing the position of the groups 
to become much more defined. We have already made use of this 
property in criticising the action of the polyoxycompounds of benzene ; 
but the action of sucrose is also that which may be expected from 
this molecule. 
