TRANSACTIONS OF THE SECTIONS. 163 



in Britain, but tlie period of incubation has not been accm-ately ascertained in 20 ; 

 and with respect to foreign birds our ignorance is still more profound. 



The author stated that he might easily extend his remarks to other heads, but 

 perhaps this was enough. He looked rather to those who had not yet adopted any 

 special branch of research to prosecute the inquiries he recommended than to 

 ornithologists of experience who were occupied in their own line, though he 

 doubted not they would countenance the view he took. 



On Instinct and Acquisition. By D. A. 8palding. 



Anatomy and Physiology. 



[For Professor Cleland's Address see page 134.] 



On a nnu Method of taJcing PJiotograjjJis of Microscopical Objects, devised 

 by Mr. Hugh T. Bowman. Illustrated by Micro-photographs of Ana- 

 tomiccd Preparations. By Heney B. Beady, F.E.S. ^'c. 



The instrument exhibited and described consisted of a small oval mirror of 

 specuhmi metal, set in a brass cap to fit over the eyepiece of the microscope at an 

 angle of 45P,- the microscope to be placed horizontally. If used for drawing 

 (instead of the ordinary camera lucida ), the reflected image was received on a 

 sheet of paper, the side light being shut out by the employment of a box blackened 

 inside or a thick cloth. For photographic purposes an ordinary photographic 

 camera was arranged, with a hole in the base instead of the end to receive the 

 microscope tube, the plate-holder being in a horizontal position. The exposure re- 

 quired for wet collodion plates, even with high powers, was stated to be very short. 



On some PJiysiological Effects of various Drinlcing- Waters. 

 By W. J. CooPEE. 



In 1870-73 M. Wurtz, the Dean of the Ecole de M^decine in Paris, presented to 

 the French Academy of Science two important papers by M. F. Papillon. In those 

 papers it was shown that the phosphate of lime in bone is capable of being replaced 

 to a considerable extent by the phosphates of strontia, alumina, and magnesia. The 

 first experiments of M. PapiUon were commenced on Monday, September 6th, 

 1869. He took a young pigeon, shut it up in a cage, and fed it with wheat rolled 

 into a fine paste, and mixed with some phosphate of strontia and a solution of 

 chlorides, carbonates, sulphates, and nitrates of potash in the proportion of 1 _ 

 gramme to the litre of distilled water ; a small quantity of hydrochloric acid was 

 also added. On the 1st of April, 1870, the pigeon was killed. An analysis of the 

 bone-ash showed : — 



Lime 46-75 



Strontia . 8-45 



Phosphoric Acid 41-80 



Phosphate of Magnesia 1-80 



Eesidue 1-10 



2 



99-90 



Another pigeon on the same date as the preceding was supplied daih' with a solu- 

 tion of phosphate and carbonate of magnesia and distilled water. Killed on the 

 4th of April. The analysis of bone-ash showed : — 



Lime 51-76 



Magnesia 181 



