TRANSACTIONS OF SECTION B. 969 
metayvanadate, a dark green liquid results, and if to this a slight excess of caustic 
soda be added, the colour of the solution quickly changes to a deep black. From 
this dark-coloured solution well-defined crystalline salts can be obtained, having a 
purple or dark green colour and metallic lustre, in which the condition of oxidation 
of the metal is intermediate between the tetroxide V,O, and the pentoxide V,O.. 
I have succeeded in preparing five distinct members of this group of salts, viz. : 
1. A soluble sodium salt having the composition 
2V,0,. V,0,; . 2Na,0 + 13H,0, 
2, A soluble potassium salt 
2V,0,. V,0, . 2K,0 + 6H,0. 
3. An insoluble potassium salt 
2V,0,.4V.,0,; 5K,0 + H,0. 
4. A soluble ammonium salt 
2V,0,.2V,0; (NH,),0 + 14H,0, 
5. An insoluble ammonium salt 
2V,0,.4V,0; 3(NH,),0 + 6H,0, 
The soluble potassium and ammonium salts may be converted into the insoluble 
by boiling the solutions for some time, either alone, or much better with potassium 
or ammonium acetate, care being taken to keep the boiling liquid slightly alkaline. 
Free mixed oxides have also been obtained. 
FRIDAY, SEPTEMBER 11, 
The following Papers were read — 
1. On the Essential Elements of Plants. By T. Jameson. 
2. The Periodic Law, as illustrated by certain physical properties of Organic 
Compounds.' By Professor THos, Carnetty, D.Sc. 
In this paper it was shown that the physical properties of the normal halogen 
and alkyl compounds of the hydrocarbon radicals exhibit numerous relationships, 
which, with one exception, are exactly similar to those which have been proved 
on previous occasions (‘ Phil. Mag.,’ July 1884 and September 1885) to exist 
between the halogen or the alkyl compounds of the elements. 
Hence the general conclusion that the physical properties of the following four 
classes of compounds (so far as investigated) obey the same rules :— 
(1) The halogen compounds of the elements, é.e., of elements with elements. 
(2) The alkyl compounds of the elements, 2.e., of elements with 
(3) The halogen compounds of the hydrocarbon radicals, hydrocarbon radicals 
(4) The alkyl compounds of the hydrocarbon radicals, z.e., of hydrocarbon 
radicals with hydrocarbon radicals. 
3. Suggestions as to the Cause of the Periodic Law ‘and the Nature of the 
Chemical Elements.? By Professor Tuos. Carney, D.Sc. 
The object of this paper was to show that the elements are analogous to the 
hydrocarbon radicals of organic chemistry, the line of argument being somewhat 
as follows :— 
1 Phil. Mag. January, 1886. 2 Chemical News. 
