HINTS ON COLLECTING AND MOUNTING OAK GALLS. 45 
A few experiments with fluids as preservatives show 
that methylated spirit or even pure alcohol is of no 
value as they extract all colours. Pure glycerine, or 
a mixture of equal parts of glycerine and water, is of 
little value. Solutions of corrosive sublimate, and also 
of formalin, are not successful mediums, for in many 
cases the leaf, the stem, or the gall itself loses more or 
less of the natural colours, and then the true value of 
the gall is deficient. 
There is, perhaps, no better record of the natural 
appearance of the galls than an accurately coloured 
drawing, or a photograph as near to, or the actual size 
of the specimens it represents. 
Fig. 1.—A pair of nippers. Fie. 2.—A pruner. Fig, 3.—A fern-trowel. 
