Mr. Worsley, in assuming office, said that, coming as he did after a man 
of such genius as Dr. Herapath, he would have to claim the indulgence of 
the members, though he could yield to no one in an earnest desire to pro- 
mote the objects for which this section of the Naturalists' Society had 
been established, and that, although a purely scientific subject was not 
always attractive, a photographic one ought to be, and it would be his 
endeavour to render the meetings as generally interesting as possible. 
Mr. Worsley then read some notes of observations made by himself 
and Mr. Gillford on the comparative solubilities of chloride, bromide, and 
iodide of silver in hyposulphite of soda. 100 parts of this dry salt would 
dissolve 90 per cent, of chloride of silver, and nearly as much bromide, 
but only about 5 per cent, of iodide, or, if the solution were heated and 
allowed to cool, about 6 per cent., the quantity being also influenced by 
the amount of alkaline iodide present. The solution of chloride or 
bromide in the hypo contained a double hyposulphite of silver and soda, 
characterised by a sweet taste, and by being only decomposed with diffi- 
culty by boiling ; while with the solution of iodide there was no 
sweet taste, and if an attempt were made to crystallise the solu- 
tion, pure iodide of silver separated out, showing that it had not 
been decomposed. Further, there was a great difference in the action of 
an excess of the halogen salt on the solution. If chloride of potassium 
were added to a solution of chloride of silver in hyposulphite of soda, no 
effect was produced; but if iodide of potassium were added to iodide 
of silver similarly dissolved, a precipitate of iodide of silver was formed, 
which could only be re-dissolved with very great difficulty by a large 
excess of hyposulphite of soda. This was very anomalous, and Mr. 
Worsley could offer no explanation of the fact, nor did any suggestion 
occur to any member present to account for it. 
ZOOLOGICAL SECTION. 
Friday, January 12.— Dr. Henry Fripp, President of the section, 
in the chair. 
The audited cash account for the past year was read, showing a small 
balance in hand. Referring to the six meetings which had been held, the 
President remarked upon the necessity for more active co-operation on the 
parts of the members of the section, if it were to be carried on satis- 
factorily, and hoped that more zeal would be shown in future. 
The election of officers of the section then took place, Dr. Fripp being 
chosen President, and Mr. S. H, Swayne the Hon. Secretary for the 
ensuing year. 
