248 



Charles Dickson Archibald, Esq., and William Robert Grove, Esq., 

 were balloted for, and duly elected Fellows of the Society. 



The following papers were read : — 



1 . — Description of a Percussion Shell to explode at the bottom of 

 the Sea. By Captain J. Norton. Communicated by S. Hunter Chris- 

 tie, Esq., M.A., Sec. R.S., &c. 



An iron tube, like the barrel of a musket, is screwed into a shell 

 of any size, water-tight. A rod of iron, about half a pound in weight 

 and a foot in length, is suspended within the tube, by means of a 

 split quill passing through a hole in the upper end of the rod, the 

 other end being armed with a percussion-cap. The mouth of the 

 tube is closed with a screw lid also water-tight. Tin or brass 

 wings being attached to the upper end of the tube will keep it in a 

 vertical position during its descent to the bottom of the sea ; and the 

 shock on its striking the bottom will cause the bar of iron within 

 the tube to fall, and produce the percussion and explosion. 



Should it be found difficult to make the shell water-proof, I am 

 satisfied that percussion powder made from silver will explode by 

 friction or percussion even when 7nixed with water. 



2. — Memorandum addressed to the Royal Society. By T. Whar- 

 ton Jones, F.R.S. 



The following is thejjnemorandum in the words of the author : — 



On the 18th of Jifne, 1835, a memoir, entitled, " On the Ova of 

 Man and Mammiferous Animals, as they exist in the Ovaries before 

 Impregnation, and on the discovery in them of a Vesicle analogous 

 to that described by Professor Purkinje in the Immature Egg of the 

 Bird," was laid before the Royal Society. 



At the time I wrote, I believed myself the first who had observed 

 the vesicle alluded to ; but by a reference to the manuscript in the 

 archives of the Society, it will be seen, from a postscript, that before 

 sending it to be communicated, I had become aware that M. Coste 

 of Paris had some time before announced that he had made a similar 

 observation, as far as concerns the rabbit. Those who are conver- 

 sant in such matters are doubtless aware that I was anticipated also 

 by Professor Valentin ; but of this circumstance I was not informed 

 till some considerable time after. 



It thus appears that, though I was an independent discoverer of 

 the germinal vesicle of the mammiferous ovum, all the share in the 

 discovery I can lay claim to historically is that of being the first who 

 pointed it out in this country. 



There is one point, however, in the anatomy of the germinal ve- 

 sicle of the mammiferous ovum of which I feel myself entitled to be 

 recognized, especially by the Royal Society, as contemporaneous 

 discoverer, and that is, the spot on the side of the vesicle. Feeling 

 this, and having heard at the last meeting of the Royal Society the 

 discovery of this spot attributed solely to the distinguished German 



