24 Mr. P. Smyth on Carbon and Hydrocarbon 



(69 obs., two thermometers) ; the direct process gave 61°*85 

 (28obs., one thermometer). Dibromaniline was prepared as 

 stated above ifi) : the direct acetic process yielded me little, if 

 any, with the same ratio of reagents. The fusion-point was 

 78°-82 (100 obs., two thermometers). Tribrom aniline from 

 acetanilide melted at 116 0, 22 (30 obs., one thermometer) ; that 

 which was made by the direct acetic process melted at 116°*28 

 (42 obs., two thermometers). 



From purified aniline only a very minute amount of monioda- 

 niline was obtained by three trials of a direct action in the ratio 



2 C 6 H 7 N : P. In presence of plumbic oxide (C 6 H 7 N : I 2 : ~) 



the yield was rather greater ; but the fusion -point of the portion 

 volatile in steam gradually rose on repeated crystallization to 

 86° and beyond, with no certain indication of a settlement. 

 This product appeared to contain traces of ordinary moniodani- 

 line ; but after the final crystallization it yielded no platinic salt 

 insoluble in alcohol and ether. The residue in the retort, non- 

 volatile in steam in presence of potash, contained aminic bodies 

 soluble in dilute aqueous hydric chloride. These are perhaps 

 the missing poly-iodanilines. 



12 Pemberton Terrace, 

 St. John's Park, N. 



III. Carbon and Hydrocarbon in the Modem Spectroscope. 

 By Viaz7A Smyth, Astronomer Royal for Scotland*. 

 [With Two Plates.] 



IN the November Number of the Philosophical Magazine 

 appears a papSr " On the Spectrum of Carbon/' by an 

 author whose name is well known and widely respected both in 

 spectroscopic inquiries in general, and carbonaceous spectra in 

 particular, viz. W. Marshall Watts, D.Sc. Yet there would 

 seem to be a something somewhere wanting in the said paper 

 if it is to represent the state of knowledge in 1874 rather than 

 1854, and to lead towards the discovery of truth as it is in 

 nature. 



The author sets out by suggesting what he considers an im- 

 proved method for astronomers in observing the rather puzzling 

 spectra of comets, viz. " to work by eye-estimations of the dis- 

 tance of the bands from the known bands of some equally faint 

 spectrum, made to occupy the lower portion of the field of view, 

 provided," says he, "a faint spectrum can be found possessing a 

 sufficient number of well-defined bands in the region of the spectrum 



* Communicated bv the Author. 



