82 TRANSACTIONS—PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
Red Field Vole {Arvicola glareolus, Schreb.)—Not improbably 
common, but the only locality I know of on the banks of the river is 
Eastwood, near Dunkeld, where Mr. Athole M'Gregor found them 
destructive to bulbs in his garden. ^ 
Water Vole {A. amphibius, L.)—Common, as is the Black 
variety. 
Common Hare t^Lepiis europaus, Pall.) Common. ^ 
Ivlountain Hare (Z. variabilis, Pall.)—As this species abounds on 
the hills, it is extremely probable that individuals occasional!} Msit 
the banks of the river, especially in winter, since they have been seen 
in the low grounds not far off. _ 
Rabbit (Z. cuniculus, L.)-Common, _ though a comparatively 
recent introduction in some parts of the Highlands, as at Taymouth, 
to which they were brought in 1820. 
4.—CHEMISTRY OF THE TAY WATER. 
By Dr. Andrew Thomson, M.A., F.C.S., F.R.S.E., F.I.C. 
(Read nth January, 1894). 
When the first paper on the physiography of the Tay \ alley v as 
o-iven last session, the President and Sir Robert Pullar both suggested 
that in order to complete these papers I should give one on the water 
of the Tay. This I hesitated to do, not from any lack of interest m 
the subject, but simply on account of the fact that my time is so full} 
occupied that it is extremely difficult to find the necessary leisure 
from professional duties to perform the careful and frequent analpes 
which must be made in order to get anything like an adequate idea 
of the exact composition, and natural and artificial impurities present 
in the Tay Water, and how these impurities make it fit or otherwise 
for the purposes for which it is chiefly used. Mr. D.^ Ferrier, F.C.S., 
one of my colleagues in the Chemical Department, kindly consented, 
however, to assist me, and the report I present is^ based chief!} on 
our own analyses, though in regard to the sanitary view of the subject 
I have been at the trouble and expense of getting three independent 
analyses from outside to establish and confirm our own report. The 
samples used on these occasions were drawn independently by two 
aentlemen, sealed up, and one handed over to us, the other being sent 
to a special analyst in a place far removed from Perth, so that ve 
have the utmost confidence in the results presented to the Society, 
and in the deductions we draw from these results. 
The Tay proper, receiving its water from Loch Tay, which is fed 
