XVI 



" The dry weather had something to do with it. 1878 was 

 " exceptionally dry. The frost came after December, and after 

 " the disease. The weather was very dry all the summer of 1878." 

 (Doom) 



" There has been more water this year than the year before, 

 " which was very dry. The river was exceptionally low two years 

 " ago. Not so low last year as the year before." (Derwent.) 



" The river was very low when the disease appeared. 



" The latter part of 1877 was exceptionally dry. The early 

 „ " part was not particularly wet. The spawning season was dry 

 " and there was no trace of disease. 



" The winter of 1878-9 was cold. 



" The water early in 1878 was low. 



" There was a deficiency of water, and the fish did not get 

 " away freely." (Tweed.) 



" When the water is low there are too many kelts." 



" The river was low and icebound last season, and this was the 

 u cause of the disease." 



" The Avater was very low. When it is low pollution has a 

 " bad effect on the fish." 



" It would have been better if there had been more water for 

 « the fish." 



Connected immediately with lowness of water in rivers comes 

 the question of land drainage, upon which point the following 

 evidence was given : — 



" The quantity of water in a river is altered by drainage. The 

 " river has changed, and is not so big as formerly. The drainage 

 " is the cause. The marshy ground is drained which used to 

 <£ keep the river up." (Tweed.) 



" The floods do not last long now. Formerly, before there was 

 " so much drainage, they continued twice as long." 



" Land drainage has done much to alter the river. If the water 

 " rose faster the floods would be higher, but they are not." 



" Drainage is for bottom water, not for surface water. The 

 " w r ater formerly got away in thousands of small streams, instead 

 " of as now in a few large ones." 



It will therefore be observed that, in the rivers where the salmon 

 disease has broken out, it has been at the time when the water 

 was low. Salmon are fish that above all things require a plentiful 

 supply of water. Lowness of water at the time they are enfeebled 

 by spawning or after spawning must necessarily have great in- 

 fluence in debilitating the fish, or as it has been ably put, " the 

 " river was too little for the fish." 



; It must also be recollected that where sewage from towns, 

 refuse from factories, &c. exist, their quantity and effect must be 

 greatly enhanced at times of low water. 



At Edinburgh evidence was given that there had been no 

 disease in the Tay, nor yet in the Forth. 



It immediately struck me that the reason of this was the pre- 

 sence, in the head waters of both these rivers, of large deep lakes, 

 which collect water in its purest possible form direct from the 

 mountains. 



