CHAP. 2. 16. COLOURS OF CLOUDS. 80 



which may be found in my Journal in Phil. 

 Mag. The colour of clouds should always be 

 noted down in meteorological journals, as also 

 the particular modification in which the colours 

 appear. I have noticed that cirri, cirrocumuli, 

 &c. at different times show different colours, 

 though in nearly the same situation with respect 

 to the sun.* 



I have often seen the nubeculae of cirrocu- 

 mulus forming in beds here and there, about 

 the time of sunset, highly tinged with crimson, 

 or with vermillion ; colours which more often 

 affect the cirrostratus and not unfrequently the 

 cirrus. 



There is one curious circumstance worthy of 

 notice with respect to the refraction of colour 

 in clouds. We often notice the light clouds, 

 cirrostrati for example, which show fine colours 

 just above the set sun and near to the horizon 



* A systematic arrangement of colours might be made as 

 well as of scents, by reference to flowers, and other standard 

 substances. It would be well if we had a nomenclature for 

 colours, which expressed them by reference to the proportion 

 of the primitive tints of which they may be compounds. In 

 the year 1813 I published several papers on the nomenclature 

 and etymology of names for colours. See Phil. Magazine, yoj. 

 xlii. pp. 119 and 327- 



