Changes caused on the Spectrum, &c. By T. Palmer. 231 
point which I wish to make quite clear. You will notice in this 
instance that band No. 1 is considerably more shaded than those 
hitherto mentioned, besides being nearer the blue end; this same 
effect occurs with bands Nos. 2 and 3, but unlike the other spectra 
they are dark and well defined, though of Class 2, or unsymmetri- 
cal, their terminations towards the blue being shaded, 
Fic. 6.—TRADESCANTIA. 
M. A. Observations. 
iL || Bets} Centre .. .. | 611:0 | Class 1. Shaded; size -3. 
2 | 21-175 a go on) || BLEW » 2. Black, shaded to the left; 
size *7. 
3 | 20°05 ‘5 532°0 » 2 Same as No. 2, though 
lighter; size °5. 
4 | 19:2 Bs SH ob. | eke nlots » 1. Shaded as No. 1, centre 
darker ; size °6. 
Band No. 4 will be seen to agree with the corresponding one 
in Fig. 4, while the general absorption, which we have noticed 
forms so characteristic a feature in all the previous spectra, is 
entirely absent. Now it is just this fact which appears to me so 
curious, for here we have a spectrum which, if I may use the 
term, includes the whole of the other spectra, and yet it is so dif- 
ferent, though to an extent. it is accounted for I think, when con- 
sidered in connection with blue Cineraria, another part also of the 
inflorescence, in which the chlorophyll is only disseminated in a 
small degree, as compared with the leaves, &c.: then, with regard 
to the comparison of blue Cineraria, Tradescantia is certainly more 
astringent, but time and experience alone will answer these ques- 
tions, and we will now pass on to consider the second part of my 
subject. ; 
. Part IT. 
You will doubtless have perceived that hitherto I have only 
taken those forms of plants which have some similarity to the 
chlorophyll itself; we will now proceed to consider briefly the 
totally different colours, such as red and yellow. 
First we have red Cineraria, which for the sake of comparison 
is prepared in the same way as the blue, and it is to this Jatter, as 
compared with the former, that I wish to call your special atten- 
tion. The spectrum, as will be seen on reference to Fig. 7, 
differs from Fig. 4 in a notable degree; but as most present, no 
doubt, recollect the inference our worthy President, in vol. xiii, 
of our researches, drew between this colouring matter and that of 
Lobelia speciosa, | need hardly pursue my investigation further, ag 
the change here is almost identical, though the general absorption, 
