THE SPEY 159 



polluters. In the Outer House Lord Kyllachy held that 

 pollution had been proved, and found that the evidence lead 

 was insufficient to show that the pursuers were adequately 

 secured by the remedial works of the defender. Time wag, 

 however, granted to further test the remedial work in an 

 attempt to satisfactorily purify the effluents. The First 

 Division, after a most extensive proof, adhered to this judg- 

 ment, and, resulting from this, various other distillers have 

 from time to time been proceeded against. 



Pot ale has been dealt with in a great variety of ways in 

 order to secure adequate purification or destruction, but it 

 has proved a very puzzling fluid to deal with. The distillers 

 offered a large reward to any one who would discover a satis- 

 factory plan of dealing with the bye-product ; but this reward 

 was not secured, so far as I am aware, although expensive 

 plant was erected at various distilleries. 



From a separate source altogether has come the demonstra- 

 tion of a quite satisfactory method. The Royal Commission 

 on Sewage Disposal, under the chairmanship of Lord Iddesleigh, 

 found it necessary to institute a thorough series of investigations 

 into the chemistry and bacteriology of the pollution of rivers. 

 Every kind of pollution was taken up and studied, and amongst 

 others a series of experiments were started at various Strathspey 

 distilleries. Dr. M'Gowan, the chief chemist to the Com- 

 mission, is, I believe, the one who, more than any other, is 

 responsible for the perfecting or adapting of bacterial filtration 

 in the treatment of pot ale, Dr. Cowie of Mortlach Distillery 

 having first carried out a number of valuable experiments as 

 to this particular method. The process is quite simple and 

 quite scientific, being in essence Nature's method carried out 

 in a conveniently concentrated manner. After a certain 

 amount of precipitation by lime, the pot ale is diluted and 

 sprinkled by an automatic arrangement on the surface of a 

 high percolating filter. The bacteria, which soon multiply 

 enormously in the filter, devour the noxious properties in a 

 few minutes, just as in a garden bed the bacteria consume and 

 convert into ammonia and nitrates the manure beneficial to 

 the surrounding plants, and which is in this form transmitted 

 to the plants. The resulting effluent gives an excellent analysis, 

 and may be run into any stream quite safely. The degree of 



