of the Fishery Board for Scotland. 



4G1 



Turning now to Table V., which gives the results obtained with 

 12 samples collected by Mr King in January 1889 off the northern 

 coast of Scotland, the values for D will be seen to range within the 

 narrow limits of 1*4576 and 1*4555, and on the other hand a reference 

 to Table VI. will show that the seven samples of surface water collected 

 in tho summer of 1888 in high northern latitudes, and kindly entrusted 

 to mo for analysis by Mr Robert W. Grey, have values for D ranging 

 between tho similarly narrow limits of 1*4720 and 1*4704. I am much 

 indebted to Mr Grey for these samples. The light thrown by their 

 composition on the matter in hand is very groat. I am now of opinion 

 that the waters in the North Sea which show a value for D approxi- 

 mating to 1*471 come from very high latitudes, if not from the Arctic 

 Ocean, and that those which show a value for D approximating to 1*455 

 come in the first instance from the surface of the North Atlantic Ocean, 

 and are moreover in all probability of southern origin. 



These conclusions appear to me to be in accordance with the observa- 

 tions made during the 4 Pommerania ' Expedition as well as with those 

 made during the recent cruise of the ' Jackal.' From the brief sketch 

 which I have endeavoured to give of Dr Meyer's Report, it will be 

 readily understood, for instance, why in the passage across from the 

 Shetland Islands to Norway, after passing over a great tract of water 

 giving values for D approximately to 1*4710, water should be met w T ith 

 closo to the Norwegian coast at Station XXVIII. giving low values for D 

 corresponding to the water met with off the Orkney and Shetland 

 Islands, and generally along the Scottish coast, While in the Shetland 

 Islands, we were still on the borders of the surface Atlantic waters of 

 southern origin ; on crossing over, we traversed a great mass of water of 

 northern or Arctic origin, and finally again met with water showing a low 

 value for D close to the coast of Norway just where it ought to have been 

 found according to Dr Meyer's view, by which surface Atlantic water 

 finds its way through the English Channel into the southern area of the 

 North Sea, passes out from this southern area as a current hugging the 

 coasts of Schleswig-Holstein and Jutland, enters the Skagerack, is there 

 deflected northwards along the Norwegian coast, where we found it. 



The samples of tho bottom water at Stations XXVIII. and XXIX. did 

 not give such high values for D as might have been expected, supposing 

 there to be an under-current of water of northern or Arctic origin flowing 

 southwards along the Norwegian coast. I do not think, however, that it 

 would be safe to draw any conclusions from these isolated results. It is a 

 matter for further investigation. 



Tho influence which the rivers draining the north of Europe have in 

 altering the composition of the sea water entering the Baltic is shown 

 in a striking manner by the results obtained with the samples collected in 

 the Cattegat, in the Sound, and in the Baltic. 



At Station XXXIV, off the Naze, the value for D was 1*4555 for the 

 surface water and 1*4567 for the bottom water, the depth being 91 

 fathoms. The water at this point, therefore, showed at surface and bottom 

 the composition which I take to be characteristic of the surface Atlantic 

 water which flows into the North Sea. The surface water was evidently 

 affected by tho outflow from the Baltic, as its density at 0° C. ( 4 S 0 ),was 

 only 1025*793, the density of the bottom being 1028*038. At Station 

 XXXV. in tho Cattegat, the density fell to 1015*854 at tho surface and 

 1026*263 at the bottom. The effect of the fresh water salts in altering the 

 relation between chlorine and density is still not perceptible in the denser 

 bottom water, the value for D found for this water being only 1*4567; but 

 in the case of the surface water it begins to make itself felt, the value 



