NATURAL HISTORY OF THE BANKS OF THE TAY. 83 
at Killin by the Dochart and Lochay, starts at Kenmore, and receives, 
a few miles farther down on its left bank, the waters of the Lyon 
from Loch Lyon. After passing Aberfeldy it is joined on the left bank, 
near Ballinluig Station, by the Tummel from the Moor of Rannoch. 
The Tummel drains Loch Lydoch, Loch Ericht, Loch Rannoch, and 
Loch Tummel, and also brings with it the waters of the Garry from 
Loch Garry. Up to this point the Tay has been flowing east by north¬ 
east, but now it turns southward, and the open valley of Strathtay con¬ 
tracts into a glen which is terminated by the Pass of Birnam about two 
miles south of Dunkeld. A little above Dunkeld the river again turns, 
now in a south-easterly direction, receiving on its right bank the Braan, 
which drains Loch Freuchie. From the Pass of Birnam the direction 
is almost due east to Delvine, when it turns north, then east, and then 
south-east to Kinclaven Castle, where on the left bank it receives the 
Isla, bringing with it the Shee, the Ardle, and the Ericht. From here 
the direction is south-west to Stanley. From Stanley the direction is 
more or less due south to the Friarton. A few miles above Perth it 
receives on its right bank the Almond, which rises to the south of 
Loch Tay and joins the main stream opposite Scone Palace. At the 
Friarton it abruptly turns east, then south-east to Newburgh, where 
the Earn, the last tributary of any importance, is received on its right 
bank. The time at our disposal has not been sufficient to enable us 
to make a separate analysis of each of these tributaries, but from the 
analyses made we are quite satisfied that, so far as natural impurities 
are concerned, there is nothing to fear in the river water. The Tay, 
in its natural condition^ is admirably adapted for domestic, dietetic, 
and general manufacturing purposes. For the brewer and aerated 
water manufacturer the water is too soft, but doubtless these know how 
to increase the hardness by the addition of lime, or possibly find a 
supply elsewhere more suitable for their purposes. 
Besides the tributaries named and marked on the map we have, 
however, a large number of unmarked tributaries, which are undoubt¬ 
edly the sources of the objectionable impurities found in our river; 
impurities which, though small in comparison with the large volume 
of water in the Tay, are yet sufficient, under certain conditions, and 
in certain states of the river, to prove hurtful to those using the un¬ 
filtered water for other than manufacturing purposes. Very little 
sewage enters at Kenmore, but in an account of a recent meeting of 
our County Council we have a paragraph, entitled the “ Pollution of 
the Tay,” in which it is shown that the crude sewage of Aberfeldy is 
run into the River Tay, and this action was even defended in a report 
signed by the Provost and Medical Officer of Health for that burgh, 
notwithstanding the fact that cases of typhoid or enteric fever were 
distinctly traceable to the use of Tay water below Aberfeldy. All 
