2 1 2 Annals of the Philosophical Club 



of the experiment. On its presence, success, which was 

 not always obtained, seemed to depend. 



March i8th, 2g6th meeting. On further discussion of 

 the alleged manufacture of diamonds, Professor Frankland 

 stated that he had recently endeavoured to find a solvent 

 for the diamond. After carefully weighing one, he had 

 exposed it to the action of the following solvents : (T) to 

 boiling pentasulphide of phosphorus (530 C.) for \ hour, 



(2) to melted cyanide of potassium at a red heat for \ hour, 



(3) to melted chloride of zinc at a red heat for | hour, (4) to 

 chrysocene 1 at low redness in a sealed tube for i hour, (5) to 

 bisulphide of carbon, heated to 320 C. in a sealed tube 

 for 6 hours, (6) to zinc ethyl in a sealed tube at 320 C. for 

 2 hours, (7) beneath melted aluminium at a white heat for 

 4 hours. After all these experiments the diamond was 

 quite unaltered in appearance and had not lost o-ooi of a 

 grain in weight. Discussion arose on the degree of con- 

 fidence to be placed on the experiments, so far as reported ; 

 some members holding that those, who claimed to have 

 manufactured diamonds, had either deceived themselves or 

 been victims of deception. Sir W. Grove said that either 

 there must have been fraud or the results must be accepted.* 



May 27th, 2g8th meeting. Mr. Hannay's paper, read 

 that afternoon at the Royal Society, on the artificial pro- 

 duction of diamonds, was the main subject of conversation. 



June I7th, 2Qgth meeting. Professor Allman gave an 

 account of the new freshwater Medusa, 3 lately discovered i 

 by Mr. Sowerby in the Victoria regia tank at the Botanic 

 Society's Gardens in Regent's Park, on which Professor 

 Lankester had read a paper that afternoon to the Royal 

 Society, and he was about to read one that evening to the 

 Linnaean Society. It was the first example of a Medusa 



1 The word is clearly written in the Minutes, but I have failed to ascertain, 

 though I have consulted a friend who is an authority on chemistry, what 

 substance is intended. 



1 This is the last meeting recorded in the first volume of Minutes. 



Accounts are given at greater length in Nature, vol. xxii. page 147'! 

 {Lankester), page 178 (Allman), and page 179 (Romanes). See also 

 under " Medusa, freshwater," in the index to that volume. 



