570 EHRENBERG ON ORGANIC MOLECULES AND ATOMS. 
when they admit of a definite numerical expression, are still hypothe- 
tical magnitudes. 
The phenomena of colours between glasses almost in contact with 
each other admit also of an inference as to the magnitudes of the so- 
called elementary particles of colours. The smallest space which gives 
the white colour was already fixed by Newton at 57-555 of an inch, 
which is rather more than >z355 of a line; and Hauy has reckoned, 
from the different refractions of light of mica, that a plate of mica 
which would produce the same effect as that of a stratum of air must 
be zpa00 Of a millimetre thick, or ggg/5g5 of a line. 
Mr. Robert Brown made several admeasurements of inorganic solid 
bodies, and also of organic ones, in the years 1827 and 1829, and fixed 
the size of the smallest particles which could be observed, and which 
he himself saw in spontaneous motion and of round form, at gpg55 t© 
so¢00 Of an inch, or 534,50 gs45 of aline in diameter. (Brief Account 
of Microscopical Observations, by R. Brown, 1828, and Additional 
Remarks on active Molecules, by R. Brown, 1829, p. 3.*) 
Sir J. F. W. Herschel says, in his Optics, 1829, p.680, that he had seen 
bodies which were magnified by an Amici’s microscope to 3000 times 
their diameter, from which however we were not at all to suppose that 
the object even approached to its solution into atoms. 
M. Dumas the chemist has however given to elementary organic 
particles very considerable magnitudes. In the year 1825 he taught, 
from his own observations, that with a good microscope the elementary 
globules of dead organic masses might be seen and counted ; that they 
formed, by means of simple combination and an augmentation of the 
mass by increasing numbers, living bodies, becoming gradually larger 
and more organized, the first forms of which were infusoria, and which 
might again be divided into the elementary parts by means of an elec- 
tric shock, by which they took a strawberry-like form (un aspect fram- 
bowsé). (Diction. Class d Hist. Natur., art. GENERATION, p. 195.) 
One of the editors of the Annales des Sciences Naturelles, who does 
not give his name, in tom. v. p. 80, 1825, fixes the magnitude of 
the elementary particles of all organic substances at 54, of a millimetre, 
or z+; Of a line in diameter. In the same work, p. 81, the author thinks 
that, in accordance with the present state of chemistry, it ispossible by 
synthetical means to prepare an artificial organic matter; and says, 
“Could we by these means obtain infusorial animalcules, Bonnet’s 
theory of reproduction would be overthrown”! 
There appeared in Kastner’s Archiv f. Naturlehre, xii. p. 348, 
1827, an express chemico-microscopical exposition by M. Kelle. He 
says, “ Zymom consists of microscopical globules, and with glyadin 
forms gluten” (p. 350). “‘ Zymom is that matter from which, by a con- 
currence of favourable circumstances, originate the lowest forms of 
* Phil. Mag. and Annals, vol. iy. p. 161, and vi. p. 161. 
