126 



Presents. 



[Jan. 9, 



cules which the impressed electromotive force can detach and send 

 off from the hot negative electrode. 



This unilateral conductivity of vacuous spaces having unequally 

 heated electrodes has been examined by MM. Elster and Geitel 

 (see ■ Wiedemann's Annalen,' vol. 38, 1889, p. 40), and also by 

 Goldstein ('Wied. Ann.,' vol. 24, 1885, p. 83), who in experiments of 

 various kinds have demonstrated that when an electric discharge 

 across a vacuous space takes place from a carbon conductor to 

 another electrode, the discharge takes place at lower electromotive 

 force when the carbon conductor is the negative electrode and is 

 rendered incandescent. 



III. " A Milk Dentition in Orycteropus" By Oldfield Thomas, 

 Natural History Museum. Communicated by Dr. A. 

 GtiXTHER, F.R.S. Received December 12, 1889. 



[Publication deferred.] 



Presents, January 9, 1890. 



Transactions. 



Berlin : — Deutsche Chemische Gesellschaft. Berichte. 1889. 



Nos. 7-16. 8vo. Berlin. The Society. 



Konigliche Preuss. Akademie der Wissenschaften. Sitzungs- 



berichte. Januar-Juli, 1889. 8vo. Berlin. The Academy. 

 Brussels : — Academie Royale de Medecine. Bulletin. Ser. 4. 



Tome III. Nos. 5-10. 8vo. Bruxelles 1889. The Academy. 

 Academie Royale des Sciences. Bulletin. Ser. 3. Tomes XVII- 



XVIII. Nos. 5-11. 8vo. Bruxelles 1889. The Academy. 



Cambridge : — Philosophical Society. Proceedings. Vol. VI. Part 6. 



8vo. Cambridge 1889. The Society. 



Elinburgh: — Royal Society. Proceedings. Vol. XVI. Pages 



257-384. 8vo. Edinburgh 1889. The Society. 



Florence : — R. Biblioteca Nazionale Centrale. Bollettino delle 



Pubblicazioni Italiane. Giugno — Dicembre, 1889. 8vo. Firenze; 



Codici Palatini. Vol. I. Fasc. 9-10. Codici Panciatichiani. 



Vol. I. Fasc. 2. 8vo. Roma 1889. The Library. 



London : — Anthropological Institute. Journal. Vol. XIX. 



Nos. 1-2. 8vo. London 1889. The Institute. 



British Museum. Catalogue of Printed Books. — Academies and 



Periodical Publications. Folio. London 1885-86. 



The Trustees. 



