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Transactions of the Society. 
The special thanks of the Society are due, not only to your 
Sub-committee who watch over this by no means easy part of our 
work, but also to those opticians who have so kindly brought here a 
large number of their beautiful instruments to exhibit the objects. 
It is also satisfactory to note that the number of papers read 
before the Society has largely increased. 
Your Cabinet of Instruments and Apparatus has been overhauled, 
set in order, and catalogued by your Curator, Mr. Eousselet, to whom 
the thanks of the Society are specially due. Your Treasurer has again 
this year devoted much of his time to your Cabinet of Objects. 
At our last Annual Meeting I remarked that a large number of 
the boobs in our Library were unbound ; it is now my pleasing duty 
to thank the anonymous donors, whose generosity has enabled us to 
bind no fewer than 110 volumes. 
Before proceeding with the work of the past year, allow me to 
acknowledge the assistance I have received from the Officers and 
Council in the work of the session. I am only expressing the views 
of the Council in thanking Mr. Parsons for the able manner in which 
he has discharged his several duties. During the past year we have 
lost our last original Fellow, Mr. John Yan Voorst, who was elected 
a Fellow of this Society no less than 59 years ago. The senior 
Fellow now on our list is Mr. G. Shadbolt, elected a Fellow in 1845, 
and President in 1856. 
In the past year we have had the concluding portion of Mr. F. 
Chapman’s valuable monograph on the ‘ Foraminifera of the Folke- 
stone Gault ’ ; and three papers on 4 Foraminifera,’ by Mr. A. Durrand. 
An important paper on £ High Befractive Mounting Media ’ was given 
to us by Mr. H. G. Madan, who, you will be sorry to hear, has lately 
met with a very serious accident. 
You have received a valuable present from Mr. H. J. Grayson, of 
Melbourne, of micrometric rulings, mounted in a high refractive 
medium, the refractive index of which is as great as that of a diamond, 
viz. 2 • 549. This subject is of so great importance that special atten- 
tion must be given to it. This importance is twofold, first the 
medium, secondly the rulings. Taking the medium first, the original 
, best known medium was that invented by Prof. Hamilton Smith ; his 
slides, however, were variable, some being stable, while others were not 
so ; he was followed by Dr. Yan Heurck, who used the same material 
with the same results. 
The next we had was by the Bev. Father Thompson, whose original 
slide is in my possession, and is still good. Some years later, Father 
Thompson published his formula, but those who have followed it 
have not been equally successful. In these experiments I strongly 
suspect it is a case of the man behind the gun. The late Dr. Meates 
was an early worker in dense media ; he used various formulae of 
his own, some of which were highly successful, while others were 
not so. 
