VIH NOTES BY THE EDITOR. 



I 



current when they are heated, this resistance increasing in a 

 determinate ratio. Efforts have long been made to invent an 

 accurate pyrometer. Experts state that this pyrometer promises 

 to be very useful. 



The new galvanic battery, invented by Bunsen, evolves no 

 fumes in working, and is quite constant. Consisting merely of 

 one liquid, a mixture of suJphuric and chromic acids, no porous 

 cells are needed. 



The experiments on the Atlantic Cable, conducted by Dr. 

 Gould, can be found on page 155. 



The general reader will be interested in the fact that mes- 

 sages were effectually and distinctly transmitted in each direction 

 by the use of an electrometer formed by a small percussion cap 

 containing moistened sand, upon which rested a particle of zinc. 



Colonel Woodward, of the Army Medical Museum, Washington, 

 has made a series of experiments in microscopic photography, 

 using the magnesium and electric lights. His results are very 

 successful. The lime light and the magnesium light had been 

 used before in this connection, in England, but not with great 

 success. 



Measurements of Newton's rings made some years since by 

 Fizeau, together with the wave length of the light of the two 

 principal components of the D line of the solar spectrum, show 

 a remarkable coincidence in results obtained by different methods, 

 and further confirm the truth of the undulatory hypothesis. (See 

 page 151.) 



We incorporate herewith the notes of Professor Nichols, on 

 the progress, during the past year, in Chemistry and Geology. 



"During the year considerable progress has been made in 

 organic chemistry so-called. As a rule, however, much of the 

 work done, and most of the results obtained, appeal to the minds 

 of a very few even among scientific men. Still these researches 

 ought not to be decried by practical men, in the face of such 

 a brilliant result as the artificial production of alizarine. (See 

 page 182.) The artificial product seems to be identical in physi- 

 cal and chemical properties with the natural coloring matter, 

 and is already manufactured on a considerable scale. Worthy 

 of mention, also, is the synthetical construction of indigo-blue, 

 by Emnierling and Engler (see page 211), although the method 

 employed offers no prospect of its production in quantities suffi- 

 cient for manufacturing purposes. Moreover, our knowledge 

 of the constitution of chemical substances, and the laws which 



