30 
Proceedings of the Eoyal Society 
2. — The Geography of the Firth of Forth, illustrated by a chart, 
pp. 46, 47. (Plate III.) 
3. — Observations on the Surface Salinity of the Firth. — Particulars 
of four water-sampling trips between Alloa and the Isle of May, 
illustrated by five curves (A to E). Effects of the flooded state of 
the rivers in November. General result , the salinity increases very 
rapidly from Alloa to Queensferry, less rapidly to Inchkeith, and 
very gradually to the Isle of May, where it decreases slightly. The 
effect of Tide, pp. 48-54. 
4. —Surface Water Density at the Marine Station. — Density varied 
slightly during July, a August, September, and October, considerably 
in November, and greatly in December. Details given, and effects 
traced to the different course of the Almond at high and low water, 
pp. 54-59. 
5. — The Bottom Water of the Firth. — Comparison of bottom and 
surface water at six places on the Firth. Result that the difference 
is greatest (tides considered) at Grangemouth, and decreases 
steadily to the Isle of May. Particular case of difference between 
surface and bottom densities at Inchgarvie, pp. 59-61. 
6. — The Alkalinity of the Firth. — Particulars given of 98 observa- 
tions. General conclusion, that the alkalinity is roughly pro- 
portional to the density, but subject to considerable variations in 
the ratio. Alkalinity of bottom water, pp. 61-64. 
It is the purpose of this paper to state, with some detail, the 
methods employed for examining the salinity and alkalinity of 
estuary water at the Scottish Marine Station at Granton ; to give 
the probable uncertainty of these methods; and to describe and 
record six months’ observations of the water of the river and 
Firth of Forth, up to December 31, 1884. 
I. Methods. 
II. Results of Preliminary Work. 
I. Methods. 
1. Collection of Water Samples. 
To collect a sample of surface water from a small boat it is 
sufficient to wash out the bottle with the water, and then hold it 
a few inches under the surface until it fills. The temperature of 
the water is taken by means of an ordinary thermometer in a 
copper case. 
On board a larger vessel the same thing may be done, the bottle 
being attached to a sounding line and lowered over the side ; but 
in the work carried on on the Firth of Forth it is desirable not to 
