438 
DR. E. FRANKLAND ON A NEW SERIES OF 
Iodide of hydrargyromethylium is a white solid, crystallizing in minute nacreous 
scales, which are insoluble in water, moderately soluble in alcohol, and very soluble 
in ether and iodide of methyl ; by the spontaneous evaporation of these solutions the 
crystals are again deposited unchanged. Iodide of hydrargyromethylium is slightly 
volatile at ordinary temperatures, and exhales a weak but peculiarly unpleasant odour, 
which leaves a nauseous taste upon the palate for several days; at 100° C. the vola- 
tility is much greater, and the crystals are rapidly dissipated at this temperature 
when exposed to a current of air. At 143° C. it fuses and sublimes without decom- 
position, condensing in brilliant and extremely thin crystalline plates. In contact 
with the fixed alkalies and ammonia, it is converted into oxide of hydrargyromethy- 
lium, which is dissolved by excess of all these reagents ; from these solutions sulphide of 
ammonium throws down sulphide of hydrargyromethylium as a slightly yellow floccu- 
lent precipitate of a peculiar and most insupportable odour. I have not yet further 
examined the reactions of this remarkable body, nor have I attempted the isolation 
of the hydrargyromethylium. 
A corresponding compound containing amyl is formed, though with difficulty, under 
similar circumstances, but I have not yet succeeded in producing one containing 
ethyl, the iodide of this radical yielding, as I have shown*, when exposed to sunlight 
in contact with mercury, iodide of mercury, and a mixture of ethyl, hydride of ethyl 
and olefiant gases. 
I have also made some preliminary experiments with other metals, and find that 
most of them are capable of thus entering into combination with the organic groups, 
methyl, ethyl, and amyl ; amongst those which thus combine under the influenee of 
light most readily, and seem to promise the most interesting results, I may mention 
arsenic, antimony, chromium, iron, manganese and cadmium. I hope to have the 
honour of laying before the Royal Society, at an early period, the results of my expe- 
riments upon these compounds. 
Imperfect as our knowledge of the organo-metallic bodies may yet appear, I am 
unwilling to close this memoir without directing attention to some peculiarities in 
the habits of these compounds, which promise at least to throw some light upon their 
rational constitution, if they do not lead to extensive modifications of our views 
respecting chemical compounds in general, and especially that interesting class termed 
conjugate compounds. 
That stanethylium, zincmethylium, hydrargyromethylium, &c. are perfectly ana- 
logous to cacodyl there can be no reasonable doubt, inasmuch as, like that body, 
they combine directly with the electro-negative metalloids forming true salts, from 
which, in most cases, and probably in all, the original group can be again separated 
unaltered, and therefore any view which may be taken of the new bodies must neces- 
* Journal of the Chemical Society, vol. iii. p. 331. 
