446 Presents. [Nov. 20, 



creasing, and at the latter time that it finally disappears. The heat- 

 ing was continued to about 840 C., and the flame was then put out. 

 In cooling, heat is liberated at one point only, and in this case with 

 a distinct rise of temperature. The recalescence begins at time 3 h. 

 47 m., temperature 750 C., and it is precisely at this time that the 

 ring begins to be magnetisable. The recalescence continues to time 

 4 h. 8 m., and at this time, and not before it, the magnetisability 

 practically attains a maximum. Before the last portion of the curve 

 the ring was heated to 966 C. Here no observations were made 

 magnetically. This part of the curve, therefore, only shows the effect 

 cf higher heating in lowering the temperature of recalescence. 



These experiments show that the liberation and absorption of heat, 

 known as recalescence, and the change in magnetic condition, occur 

 simultaneously. Also that in the case of steel with 0'3 per cent, of 

 carbon both temperatures of liberation of heat are associated with 

 change of magnetic condition. 



Presents, November 20, 1890. 

 Transactions. 



Baltimore: Johns Hopkins University. Circulars. Vol. IX. 



Nos. 81-82. 4to. Baltimore 1890 ; The Negro in Maryland. 



By J. B. Brackett. 8vo. Baltimore 1889. The University. 

 Berlin : Deutsche Chemische Gresellschaft. Berichte. Jahrg. 



XXIII. Nos. 1-9. 8vo. Berlin 1890 ; Verzeichniss der Mit- 



glieder, Januar, 1890. 8vo. Berlin. The Society. 



Gesellschaft fur Erdkunde. Verhandlungen. Bd. XVII. Nos. 



4-7. 8vo. Berlin 1890 ; Zeitschrift. Bd. XXV. Heft 3-4. 



8vo. Berlin 1890. The Society. 



K. Preuss. Akademie der Wissenschaften. Abhandlungen. 1889. 



4to. Berlin 1890. The Academy. 



Bremen : Naturwissenschaftlicher Verein. Abhandlungen. Bd. 



XI. Heft 1-2. 8vo. Bremen 1890. The Verein. 



Brussels : Academie Boyale de Medecine de Belgique. Memoires 



Couronnes et autres Memoires. Tome IX. Fasc. 3. Tome X. 



Fasc. 2-3. 8vo. Bruxelles 1890. The Academy. 



Calcutta : Asiatic Society of Bengal. Journal (Nat. Hist.). 



Vol. LVII. Part 2. No. 5. 8vo. Calcutta 1890; Vol. 



LIX. Part 2. No. 1, with Supplement. 8vo. Calcutta 



1890; Journal (Philology). Vol. LVIII. Part 1. Sup- 

 plement. 8vo. Calcutta 1890 ; Vol. LIX. Part 1. . Nos, 1-2. 



8vo. Calcutta 1890; Proceedings. 1890. Nos. 1-3. 8vo. 



Calcutta. The Society. 



Indian Museum. Notes on Indian Economic Entomology. Vol. 



I. No. 4. 8vo. Calcutta 1890. The Museum. 



