SECTIONAL TRANSACTIONS.—B. 307 
the rate of gas evolution is very small (approx.0.2c.c. per hour), indicating that second- 
ary reactions have taken place. During the main period of the experiment, the 
decomposition of the diazonium chloride followed the course of a unimolecular reaction. 
The decomposition of the diazonium nitrate closely resembles that of the chloride ; in 
the case of the sulphate, however, the reaction is more rapid at the beginning, and the 
total evolution of gas smaller, showing increased secondary reaction. The anion in 
some cases therefore appears to influence the rate of decomposition, unlike the results 
with benzenoid diazonium salts. (Cf. Cain; Ber., 1905, 38, 2511.) 
According to Cain and Nicoll (J.C.S., 1902, 81, 1412) the most stable benzenoid 
diazonium salt of a wide range of aromatic bases investigated by them was that from 
o-nitro-aniline. We have found that the diazonium chloride from 4 amino 1-Phenyl 
3-5 dimethylpyrazolene is of the order of six times the stability of the above-mentioned 
benzenoid salt at 100° C. This compound, it might be noted, is not the most stable of 
the heterocyclic diazonium salts (e.g. 3-5 dimethyl pyrazole diazonium chloride), and 
further work on this substance is in progress. 
10. Dr. J. B. Fiera and Mr. H. A. Fretits.—Some Modifications of 
Form of Sodium Salts expressed from Acid Gel during Drying. 
Clear silicic acid gel produced by the addition of solutions of hydrochloric acid, 
hydrobromic acid, nitric acid, and hydriodic acid respectively to pure sodium silicate 
solution were dried in a desiccator in vacuo. The sodium salts were expressed from 
the gel in needle-like formations. 
Sodium Chloride —Long clear needles—majority in the form of capillaries showing 
weak birefringence and an extinction approximately parallel to the length of the 
needle. 
Sodium Bromide—Clear needles showing high double refraction and anisotropic 
colours: angle of extinction 8-9°—monoclinic, very~ unstable, becoming opaque 
owing to conversion into rhombic form. 
Sodium Nitrate—Long clear needles—stable—angle of extinction 41°. 
Sodium Iodide.—Needle-like formation but opaque. 
Potassium Iodide—Silicic acid gel impregnated with a solution of potassium 
iodide ; on drying, the potassium iodide was expressed as fine silky hairs very much 
distorted. 
The first three specimens show strain structure under the microscope. 
Tuesday, September 1. 
11. Discussion on The Alternating Effects in Carbon Chains. 
_ Speakers: Dr. B. Frirscuei, Prof. A. Lapwortn, F.R.S., Prof. 
R. Rostnson, F.R.S. 
Dr. B. FLirscHerm. 
An alternating effect in carbon chains is now generally admitted. Does it consist 
of alternating amounts of free and bound affinity force (* affinity theory ’), or of varying 
distributions of electrons (‘ polarity theory ’) ? 
The polarity theory defines the attractive force between non-ionised atoms as an 
electrostatic attraction between shared electrons and the atomic nuclei. But instead 
of forming a bridge between the physical structure of the atom and its chemical 
behaviour, this conception creates difficulties both physical and chemical. Physically, 
it conflicts with the Rutherford-Bohr-Sommerfeld theory, as evidenced by the failure 
of attempts to devise even a stable hydrogen molecule model with shared electrons ; 
by the impossibility of obtaining identical frequencies in a sub-group of carbon 
electrons if these were shared with ‘ electro-negative ’ atoms differing materially from 
each other in their outer electronic frequencies ; by the racemisation of asymmetric 
carbon without rupture of bonds; by the difficulty of reconciling shared electrons 
a 
