570 EHRENBERG ON ORGANIC MOLECULES AND ATOMS. 



when they admit of a definite numerical expression, are still hjpothe- 

 tical magnitudes. 



The plisenomena 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 yyj'ooo °^ ^" inch, 

 which is rather more than ^ ^ (^ m, 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 4iio'()oo ^^ ^ millimetre thick, or 9 „ o'o ^^ ^ ''"^• 



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 goOTo ^° 

 5o(Too of an inch, or ^0^00*° ^sVo offline in diameter. (Brief Accmmt 

 of Microscopical Observations, by R. Broum, 1828, and Additional 

 Remarks on active Mohcides, by R. Brown, 1829, p. 3.*) 



Sir J.F. W.Hei-schel says, in his Optics, 1829, p. 680, thathehad 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 

 tiie 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- 

 boise). (^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 paiticles of all organic substances at 3^ of a millimetre, 

 or ^^ of a line in diameter. In the same work, p. 81, the author thinks 

 that, in accordance with the present state of chemistry, it is possible 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. Kcelle. 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. iv. p. 161, and vi. p. 161. 



