134 ANNUAL OF SCIENTIFIC DISCOVERY. 



and that of another? 3. Do the stars scintillate less feebly on the peak of 

 Teneriffe than when observed from the plains below, as in the case of Mount 

 St. Bernard? 4. It would be interesting to observe, upon ascending the 

 peak of Teneriffe, whether the stars Achernard and Canopus, which arc 

 invisible in our latitudes, scintillate more or less intensely than certain other 

 stars of comparable magnitude. I hope that you will be able to continue 

 the prosecution of the interesting observations which you have commenced; 

 and since for this expedition it is necessary to obtain the authorization of 

 the government, which must possess adequate materials for forming an 

 opinion beforehand of the importance of the expedition, you might suggest 

 the scintillation of the stars as an additional phenomenon to be observed at 

 that exceptional station. I was glad to learn that on the peak of Teneriffe 

 the stars appeared to scintillate faintly. This was exactly conformable to 

 the observations I made during my residence at St. Bernard, notwithstand- 

 ing that the altitude was much less considerable (only 2480 metres). It coin- 

 cides in every respect with the results at which I have arrived. I continue 

 to pursue my observations as formerly, and labor at their reduction ; but 

 when there are more than 20,000 observations to compute in various ways, 

 to combine by the hour, by the day, and according to certain meteorological 

 conditions, the labor is immense, and cannot certainly be accomplished in 

 less than several years. The explanation of the phenomenon of scintillation 

 proposed by M. Montigny appears to me admissible, and equally probable 

 with that offered by myself, according to which I attribute the faint scintilla- 

 tion of red stars in the circumstance that the red wave being the greatest 

 wave, it would less readily interfere, and, consequently, would with greater 

 difficulty be destroyed, or increase in intensity. Perhaps the only mode of 

 deciding between these two explanations would consist in observing the 

 scintillation of violet stars. If the theory of M. Montigny is correct, a violet 

 star, like a red star, ought to scintillate less feebly, because it is composed of 

 homogeneous light. If, on the other hand, my explanation of the phenome- 

 non is Avell founded, the violet star ought to scintillate more intensely than a 

 white star, because the violet wave is the smallest wave. Unfortunately, 

 there is no violet star sufficiently bright for such comparative observations. 

 Accordingly, at present, I do not wish to pronounce between the two expla- 

 nations, each of which appears to me to be possible. But precisely this 

 question and others suggested by the scintillation of the stars prove that 

 the study of the subject may possess a high degree of interest in several 

 respects. 



INFLUENCE OF LIGHT ON THE RESPIRATION OF THE LOWER 



ANIMALS. 



M. Beclard, of France has recently made some curious experiments on 

 the Influence of Light on Animals and finds that those creatures which 

 breathe from the skin, and have neither lungs nor branchiae, undergo remark- 

 able modifications under different colored rays. He exposed the eggs of flics 

 (^fl<sca carnarvi] under bell-glasses of six different colors: little maggots 

 were hatched from all ; but those under the blue and violet rays were more 

 than a third larger than those under the green. Frogs, which by reason of 

 their naked skin, are very sensitive to light, give off half as much more car- 

 bonic acid in a given time under the green ray as under the red; but if the 

 frogs are skinned, and the experiment is repeated, the excess is then with 



