It was in November 1854 that the Institute saw the wisdom of amalgamation with the Philosophical Society, which had been founded in the meantime, as 'the existence of two separate societies caused a division of the forces which might be brought to bear upon the same subjects, and the colony was hardly able to support adequately the two separate institutions having the same objects'. By January 1855, they were ready with a definite proposal. This proposal was apparently received rather coldly at first by members of the Philosophical Society who apparently felt they had little to gain by such an amalgamation. However, after considerable negotiation between the two bodies, amalgamation finally took place with a new body, the Philosophical Institute of Victoria being formed, the last meeting of the old Institute taking place on 7 June 1855.

The amalgamation was obviously not unanimous as far as the members of both societies were concerned, although it was the obvious course to follow. For many years after amalgamation, bitter controversies raged between individuals. Perhaps the most unco-operative was the original founder of the Victorian Institute, Sidney Gibbons. The following extract from his papers found after his death clearly illustrates this—

A little after I formed my Institute, some official formed a club at the Lands Office. Seeing my success, this club opened its doors and became a competitor with the public under the name of the Philosophical Society. After a year or more of their competition the Victorian Institute proposed and ultimately effected an amalgamation only to find the Philosophical Society was moribund and in debt.

Royal Society of Victoria