124 Intelligence and Miscellaneous Articles. 



or near the centre of each gronp, crystallization was set up, giving 

 rise to a radiating fibrous structure, which gradually developed zone 

 after zone of divergent fibres until the entire mass of primitive 

 spherulites was permeated by this secondary structure — a structure 

 engendering a molecular rearrangement of the mass, such as would 

 obliterate any trace of structure which the primitive spherulites 

 might have originally possessed. 



In a supplementary note the views of Mr. J. P. Iddings with refer- 

 ence to the spherulites in question were given. Mr. Iddings considers 

 that the structures here described as primary are of secondary origin. 

 The author stated in detail his reasons for adhering to the conclu- 

 sions given in this paper. 



3. " A Monograph of the Bryozoa (Polyzoa) of the Hunstanton 

 Red Chalk." By George Robert Vine, Esq. 



4. " Evidence furnished by the Quaternary Glacial-Epoch Mo- 

 rainic Deposits of Pennsylvania, U.S.A., for a similar mode of* 

 formation of the Permian Breccias of Leicestershire and South 

 Derbyshire." By William S. Gresley, Esq., F.G.S. 



The author noted that nodules of ironstone occurring in the 

 Pennsylvanian glacial deposits of Quaternary age are scratched in 

 precisely the same manner as those which he has described from the 

 Permian deposits of Leicestershire and Derbyshire, and concluded 

 that one and the same agency, viz. ice, has been instrumental in 

 producing the observed results in both cases. 



XI. Intelligence and Miscellaneous Articles. 



DIAMAGNETISM TESTED BY CAENOT's PRINCIPLE. THEOEETICAL 

 PREDICTION. BY J. PARKER, M.A., FELLOW OF ST. JOHN'S 

 COLLEGE, CAMBRIDGE. 



IN May 1889 I published a short paper in the Philosophical 

 Magazine in which Carnot's principle was applied to diainag- 

 netism. An oversight occurs in the paper which has since been 

 corrected by M. Duhem, who has adopted and extended the sub- 

 stance of the paper. 



The present state of experiment and theory on diamagnetism 

 may be briefly stated thus : — 



(1) If a piece of bismuth be placed near a strong iron magnet in 

 the open air, the bismuth behaves as if repelled by the iron. 



(2) If the same experiment were performed in a vacuum, it is 

 shown by Carnot's principle that the bismuth would not be repelled 

 and might be attracted. 



We therefore conclude that if the experiment were performed in 

 a place from which the air could be pumped away at will, the 

 repulsive force on the bismuth would become zero when the pres- 

 sure of the air was sufficiently reduced, and by continuing the 

 exhaustion still further it would probably become attractive. 



