1894] MICROSCOPICAL JOURNAL. 127 



tract the sporangia-bearers. This condition only lasts for some 

 hours, and then it disappears. 



We know that a number of non phosphorescent bodies emit 

 rays of light after having been under influence of light. The 

 duration of this condition varies from a few minutes to 24 hours. 

 Metals such as steel or iron are not phosphorescent, but we have 

 here a new form of phosphorescence, which might be called 

 dark phosphorescence. It is the light and not the heat which 

 produces the said effect upon the metals ; the color of the rays 

 do not seem to have any influence upon producing the effect 

 described above, in the metals. 



Zinc becomes active by heating alone, and when experiment- 

 ing with this body, Elfving found that it becomes positive ther- 

 motropic. On copper, cobalt, nickel, tin, lead and glass heat- 

 ing like above alone did not produce the activity, these metals 

 being heated until the}' are nearly melting, and then allowed to 

 cool so far that the hand could not feel the heat. 



Elfvings conclusion is: Es scheint mir dann wenig befrem- 

 dend anzunehmen dass auch Molekularscliwingungen, welcke 

 den Rorpern selbst innevohnen oder irgend eine in denselben 

 slattfindende Veranderung begleiten, ahnliche physiologische 

 Wirkungen hervarrufen Konnen. Was speciell die Metalie be- 

 trifft, zeigt uns ja auch die Metallotherapie Wirkungen, die 

 entschieden fur solche sprechen. Mrs. Dora Bav. 



MICROSCOPK AL NOTES. 



T. D. A. Cockerell is now curator of the museum at the Is- 

 land of Jamaica. 



G. 'W. Rafter, one of our valued contributors, has recently 

 written a book on Sewage Disposal which has been publislied 

 by Van Nostrand. We have not yet seen a copy. 



MICROSCOPICAL SOCIETIES. 



^A«^ashington, D. C, L. M. Mooers, Secretary. 



Ajvil 10, 1894. — In spite of a heavy rain storm, seven mem- 

 bers were present, Dr. Gibbs in the chair. The Soiree Commit- 

 tee reported the arrangements for a Soiree at the High Schoo] 

 building May 8th. Mr. Smiley showed photographs of blood 



