200 Annals of the Philosophical Club 



showing what a perfect insulation a good vacuum is. Mr.. 

 Huggins mentioned that Mr. Crookes had told him he was 

 now convinced the effects were due to residual air, so that 

 there would be no rotation of the vanes if the vacuum were 

 perfect. Also he had found a degree of rarefaction at which 

 the effects of rotation reached a maximum, beyond which 

 they diminished. 



Nov. 23rd, 265th meeting. Sir James Paget mentioned 

 a case, which he had recently come across, where embryonic 

 characters were retained in many members of the same 

 family. It was known that the branchial fissures found in 

 the early stages of embryonic life, instead of closing in the 

 later, were retained as small blind sinuses in the neck, the 

 existence of which was betrayed by their exuding little 

 drops of white mucus, by which, whenever the possessor was 

 affected by catarrh, the outside of the throat was smeared ; 

 the reason being that, though not in direct connexion with 

 the bronchial membrane, they sympathized with it. In this 

 particular case the anomaly existed in a gentleman, his 

 father, his sister, and four of his eight children. It was 

 accompanied by another embryonic condition, which he 

 believed had not hitherto been observed, namely a sinus 

 on the upper part of the helix of the ear, large enough to 

 admit a very fine probe. This was, he believed, a relic of 

 the second branchial fissure. Five of the children had this 

 peculiarity. 



Mr. Sclater stated that he had just received from the 

 Marquis G. Doria information of the discovery of a large 

 species of Echidna on Mount Arfak in New Guinea. This 

 was an important fact, for hitherto it had been believed that 

 the monotremes were restricted to South-east Australia 

 and Tasmania. 



Dec. 2ist, 266th meeting. Professor Abel described ex- 

 periments with shells when the bursting charge was contained 

 in a small metal cylinder, and the space between it and the 

 inner surface of the shell was filled with water. These experi- 

 ments, of which he gave particulars, showed that the shell 

 burst into a much larger number of fragments than if it had 



