North- West Coasts of Sutherland and their Bird Life. 485 



The question as to whether the presence of these Diatoms 

 is in itself hurtful, or points to contamination of the water in 

 which they are found, is a point of some importance. It is a 

 well-known fact to all those who are experts in water 

 analysis, and in the examination of streams for pollution, 

 that the presence of vegetable life is not in itself hurtful 

 provided it consists of those forms, mostly green in colour, 

 found in pure waters. It is also admitted that where a 

 water becomes contaminated with putrescent matters, the 

 character of the flora entirely changes. The Diatomacea 

 belong to the first of these classes, and are especially found 

 in waters which have for their collecting ground rocks of an 

 igneous or metamorphic origin. They are therefore rather 

 an evidence of the purity of a water supply, and their 

 presence need not be the cause of any alarm. A properly 

 constructed sand filter will readily cause their removal. 



XLIV. The North- West Coasts of Sutherland and their 

 Bird Life. By John A. Harvie-Brown, Esq., F.RS.E., 

 F.Z.S., etc.. President. 



(Read 20th May 1885.) 



The district about which I intend to treat in the present 

 paper is one little spoken of by naturalists. It extends from 

 Ehiconich round the shore, following the deep sea loch of 

 Inchard, including the coast between that and Cape Wrath, 

 and the outlying islands of Bulgie and Eona, and other rocks 

 and skerries ; and again eastward from Cape Wrath to 

 Whiten Head at the eastern entrance to Loch Eriboll. 



After traversing the long stage between Lairg and Durness 

 on the 9th June 1882, a drive of upwards of 60 miles, I 

 took up my quarters at Durness, from which point I intended 

 to visit the north coast. 



I passed through the wild strath of Dionard. The Edder- 

 achyllis district of Sutherland somewhat alters in its physical 

 aspects when the traveller gets north of Loch Laxford. H« 

 sees no more of the richly-clad birch slopes round the lochs 

 by the road side, so common south of Scourie, but instead, he 



