The improbability of a similar "accommodation " in the 
fish's eye was argued on anatomical and physiological 
grounds, emphasis being laid on the absence of a ciliary 
muscle, the non-development of the ciliary proce-f>es, the 
form, position, and structure of the lens, and the immobility 
of the iris and pupiUry opening. The supposed relation of 
the "choroid gland" to any function of "accommodation" 
was negatived by consideration of the static condition of the 
circulation in the vessels of the. "gland," and the author 
attempted to show that this static condition of the circula- 
tory blood stood in direct relation to the varying pressure 
on the surface of the fish's body at varying depths under 
the surface of the water. The meaning of this peculiar 
arrangement of vessels was thus interpreted in connexion 
with the dynamic force exerted by the heart in propelling 
its contents through the system under varying pressure on 
the surface of the fish's body, of which surface the cornea of 
the eye formed a part. Allusion was made to the peculiarity 
of venous circulation in fishes and mammals which live 
under water. 
In conclusion, Dr. Fripp proposed the following theory 
1. That the fish's eye was in its normal state arranged for 
vision of near objects, and that the great refractive power 
of a prolate spheroid lens such as exists in the fish was 
adequate to the production of a picture at short fDcal dis- 
tances even with ravs of light passing through so dense a 
medium as water, 2. That there was no accommodation of 
the fish's eye for extended limits of vision. 3. That the 
passive state of the fish's eye being that in which it is 
J enabled to see objects near and at moderate dis- 
i tance, no active or physiological change for accommoda- 
tion of sight for distant objects took place or seemed 
necessary. The dioptric arrangement being the reverse 
of that which obtains in animals where " accommodation" is 
observed, and in whom the passive state is that of vision 
arranged for distant objects, wbilst the active state is that of 
vision accommodated at will for near objects. 4. That the 
vascular distribution of the choroid vessels has no relation 
to any movement of the lens or change of its shape, but is 
arranged to meet the changes of static condition of the cir- 
culating fluid and of dynamic force exerted by the heart 
under varying pressure from without, and that, by such an 
arrangement, protection to the delicate tissues of the eye is 
afforded by a compensating b^ilance between the tension of 
the blood within the vessels and the external pressure 
exerted upon them. 
In thanking Dr. Fripp for his exhaustive paper, the 
President remarked upon the profound thought and condensa- 
tion of a large amount of observation displayed in it, and 
spoke of the honour thus reflected upon the society, as well 
as of the highest credit being due to the author. 
Mr. W. L. Carpenter then read two short communications^ 
the first being entitled "Note on Pbaroah's Serpents' 
Eggs." The author recapitulated, in general terms, the 
results of the analyses of the serpent and its egg, lately 
brought before the Chemical and Photographic Section, and 
insisted strongly on the danger of burning them in small 
rooms with little ventilation, on account of the large amount 
(one-seventh) of the mercury contained in the egg being 
volatilised, and he alluded to the ill effects he and others 
had observed to arise from them. He mentioned the insi- 
dious and distressing symptoms of poisoning by mercury 
vapour, and concluded by describing what be believed 
to be the reason of the fantastic forms and ex- 
traordinary increase of bulk sustained by the sulpho- 
cyaoide of mercury when decomposed by heat. The 
secjnd was a note upon the artificial formation of flint. 
After briefly alluding to the various natural deposits of 
ssilicd, and the nature of some of the compounds of silicic 
acid, Mr, Carpenter said that in decomposing on a large 
scale a solution of silicate of soda by a mineral acid on one 
occasion, the silica, at first gelatinous, became quickly 
