.60 PEOCEEDINGS OF SOCIETIES. [^Sna^i^y fim' 
an exceedingly interesting branch of inquiry, wMch could only be 
successfully prosecuted with the micro-spectroscope, since the quan- 
tities of the coloured bodies were too small to admit of chemical 
analysis. He protested very strongly against the notion ventured on 
by Mr. Hogg, that thallium had anything to do with the chlorophyll 
spectrum; indeed he hardly believed that he had heard Mr. Hogg 
aright. As to the occurrence of copper in the Turacou's feather, its 
discovery had nothing whatever to do with the spectroscope, as Mr. 
Hogg had stated, but was made before its spectrum was known ; * and 
the spectrum, now that it is known, has nothing to suggest copper 
about it. It is a very grave error to fall into to suppose that the 
absorption spectra of coloured bodies are due to metallic ingredients, 
they are simply caused by certain combinations of the organic elements 
composing those bodies. He must also differ entirely from Mr. Hogg 
as to the interest or value of the experiment made with a diseased 
crystalline lens. It is not possible to distinguish quantitatively by 
means of the spectroscope at all (even Preyer's recent proposition as 
to estimation of haemoglobin being objectionable), and Mr. Lankester 
believed that no one who knew the abundance of sodium in animal 
tissues would credit Mr. Hogg's assertion that he could distinguish an 
increase of sodium in the cataract-lens by means of its flame-spectrum. 
A vote of thanks was then passed to Mr. Hogg. 
The President announced that Mr. Browning had prepared a short 
description of a new form of micro-spectroscope which he had made, 
and by which the most effective results could be obtained, at the very 
low price of 22s. 6d. 
Owing to the late hour at which the announcement was made, it 
was ordered that the paper be taken as read. 
A paper by Mr. Carruthers, " On the Structure of the Ulodendron," 
was taken as read, and will appear in the journal. 
The President announced that the next meeting would be on the 
13th of October, and intimated that during the month of August the 
library would be closed as usual. 
Donations to the Library, June 9, 1869 : — 
From 
Land and "Water. Weekly Editor. 
Scientific Opinion. Weekly Editor. 
Journal of the Society of Arts Society. 
The Student Publisher. 
The Canadian Journal (?) 
The Microscope. 7th Edition Author. 
John Armstrong Purefoy CoUes, M.D., F.E.C.S.I., was elected a 
Fellow of the Society. 
Walter W. Eeeves, 
Assist. Secretary. 
* Professor Church, who discovered Turacine, does not seem to agree with 
Mr. Lankester on this point. In his account of the matter in the ' Student ' 
(vol. i., p. 165), he describes his experiments on Turacine with the spectroscope, 
and states that the resemblance of its spectrum to that of cruorine induced him to 
test for iron. He adds that, on applying potassic ferro-cyanide to a solution of 
the ash of the pigment, "he was astonished that, instead of the deep blue of the 
ferric-ferro cyanide, the rich purple brown precipitate of the cupric ferro-cyanide 
was at once seen." — Sec. R. M. S. 
