341 



of a positive proof. If the second be true, it might be expected that 

 the light from the edge of the solar disk would exhibit more of these 

 absorption bands than that from the centre, which must have traversed 

 a smaller amount of atmosphere ; but such was not found to be the 

 case. The third supposition is favoured by the fact that the atmo- 

 sphere has unquestionably much to do with the manifestation of many 

 of these lines, and by the analogy of the bands produced by nitrous 

 acid gas, bromine vapour, and other absorbent media. The expert- 

 mentum crucis of observing an artificial light through a long space of 

 air was attempted by means of the revolving light on Beachy Head, 

 as seen from Worthing at a distance of twenty-seven miles. It gave 

 a negative result ; but on account of the great difficulty of detecting 

 slight breaks in a faint thread of light, no great reliance is to be placed 

 on the experiment. A similar doubt rests on the authors' observa- 

 tions of fixed stars, and on the non-recognition by Fraunhofer of the 

 ordinary lines in the light of Sirius and Castor, while on the other 

 hand he did detect D and b in that of other stars. The origin of 

 these lines is still an open question. 



The spectra of artificial flames sometimes exhibit bright lines 

 coincident with the dark spaces of the solar spectrum. Thus the 

 yellow band in the flames of soda, and several other substances, is 

 identical in refrangibility with D ; but the most remarkable case is 

 that of charcoal or sulphur burnt in nitre ; the spectrum shows three 

 very prominent lines, two of which coincide with A and D, while a 

 faint red line appears at B, and a group between it and A. 



A map is also given of the bright lines, principally orange, that 

 make their appearance when nitrate of strontia is placed on the 

 ignited wick of a spirit-lamp. 



IV. " On some New Volatile Alkaloids given off during Putre- 

 faction." By F. GRACE CALVERT, Ph.D., F.R.S., &c. Re- 

 ceived February 23, 1860. 



Some eighteen months ago my friend Mr. J. A Ransome, surgeon 

 to the Royal Infirmary, Manchester, induced me to make some 

 researches with the view of ascertaining the nature of the products 

 given off from putrid wounds, and more especially in the hope of 



