of Edinburgh, Session 1885 - 86 . 
965 
Those elements, which resemble one another and which we can 
pick out, taking every eighth one from that one we start with, from 
what he calls a group (see table). In vertical series are arranged the 
groups of similar elements, and the series , each of seven elements, 
are seen on the horizontal lines. There is one other point of import- 
ance • it is that the elements of a group which are in an even series 
are especially related one to another in these properties. So, in like 
manner, elements belonging to the same group of odd series are espe- 
cially related. Thus Li, Ha, K, Cu, Kb, Ag, Cs, Au have all of 
them properties in common ; but in this group, Ha, Cu, Ag, Au are 
most alike, and Li, K, Kb, Cs also, in like manner, are specially 
related. 
By far the greater number of sapid substances contain elements 
found in Groups I., II., and VII., and these I accordingly studied. 
The salts of Group I. and II. most easily obtained are the chlorides 
and sulphates, and of Group VII. I selected the combinations these 
elements form with sodium and potassium. As it was very neces- 
sary to use salts as pure as possible, many were prepared for me 
with great care by Mr Harris the chemist, but for the greater 
number I have to thank my colleague Dr Hicol, who placed at my 
disposal a large collection of very pure salts prepared by himself for 
his own well-known investigations on solubilities. In the subjoined 
tables are the results of an investigation of Groups I., II., and VII. 
We have then to see whether the same taste sensations are produced 
by the chlorides, &c., of elements having similar physical properties. 
Gaoup I. 
Metal. 
Chloride. 
Sulphate. 
L 
Salt. 
Sal. Bit. 
Na 
Salt. 
Sal. Bit. 
K 
Salt. Sal. Bit. 
Sal. Bit. 
Cu 
Insol. 
Sal. Bit. Ast. 
Rb 
Salt. Sal. Bit. 
Ag 
Insol. 
Sal. Bit. 
Cs 
Salt. Sal. Bit. 
Au 
Salt. Ast. 
It will be seen that all the soluble chlorides are salt like table 
salt, although with the higher numbers we have the taste becoming 
more saline, A very slight bitter taste also develops. Some salts 
