1 46 Proceedings of the Royal Society 
This observation was made for the first time by the spectrum 
produced by the deflagration of nitre, and I afterwards found that 
this was a property belonging to every such flame.* 
This result was obtained from experiments made at St Andrews 
in 1842, on nearly 180 substances, deflagrated in a platina cup by 
a mixture of oxygen and coal gas. A notice of these experiments 
was read at the meeting of the British Association at Manchester 
in 1842. The journal containing them was laid before the Physi- 
cal Section, and one or two of the more interesting results were pub- 
lished in the reports of the Association for that year. The object 
of these experiments was merely to discover new facts for future 
investigation, and hence the place of the bright lines was simply 
estimated by the eye. Other pursuits, of a less laborious kind, pre- 
vented me from determining the exact places of these lines in 
those flames where their number and position were most re- 
markable, but this will now be better done by some of those 
numerous observers who are working so successfully with the spec- 
troscope. 
The following specimens of these observations will show their 
limited character, and how far they may be useful and suggestive 
to future observers : — 
1. In the Chlorides of Tin and Lead. The whole spectrum was 
covered with splendid lines, the double line D being conspicuous. 
2. In the Ammonio-Chloride of Platinum. The colour of the 
flame yellow , and fine lines chiefly in the red and green spaces. 
3. Acetate of Strontites. Colour of the flame yellow. Fine red 
and orange lines near D, and one fine blue line, and an extreme red. 
4. Acetate of Lime. Flame brown. Many fine lines, and a 
large green and red one on each side of D. 
5. Chromate of Ammonia. Fine green and red bands near D. 
6. Lithoxanthate of Ammonia. Fine lines throughout the whole 
spectrum, with a fine bright blue band. 
7. Superacetate of Lime. A fine blue line in the extreme violet; 
and an orange and green band equidistant from D. 
8. Tartrate of Potash and Antimony. Flame brilliant blue. 
The extreme red finely insulated. 
* Report of the British Association for 1842, p. 15. 
