' Scientific Reviews. 199 
ing to theoretical views, that is to say, to the particular nature and 
functions of these granules, or to their mode of action in nature, 
Mr. Brown does not appear to adopt the ideas of Mr. Brongniart. 
The commissioners, after having observed the facts with all the care 
in their power, and driving from their minds all systematic consider- 
ations, came to the unanimous conclusion with Mr. Brongniart and 
Mr. Brown, that the causes to which Mr. Raspail attributes the 
motion of the granules exert no influence. 
The commissioners further stated, that the resemblance which 
certain active molecules of Mr. Brown present to the spermatic 
granules of Mr. Brongniart, furnish strong presumption against the 
hypothesis of the latter. | 
But Mr. R. Brown’s remarks on Mr. Brongniart’s essay do not 
coincide with the first statement made by the commission, and es- 
tablish some important distinctions. For he particularly says :— 
< He (Mr. Brongniart) was evidently unacquainted with the fact, that the ac- 
tive spherical molecules generally exist in the grain of pollen along with its proper 
particles; nor does it appear from any part of his memoir that he was aware of 
the existence of molecules having spontaneous or inherent motion, and distinct 
from the peculiar particles of the pollen, though he has doubtless seen them, and 
in some cases, as it seems to me, described them as those particles. 
“¢ Secondly, He has been satisfied with the external appearance of the parts in 
coming to his conclusion, that no particles capable of motion exist in the style 
or stigma before impregnation. 
“¢ That both simple molecules and larger particles of different form, and equal- 
ly capable of motion, do exist in these parts, before the application of the pollen 
to the stigma can possibly take place, in many of the plants submitted by him to 
examination, may easily be ascertained, particularly in Antirrhinum majus, of 
which he has’given a figure in a more advanced state, representing these mole- 
cules or particles, which he supposes to have been derived from the grains of pol- 
len, adhering to the stigma.”’ 
Mr. Raspail, in the mean time, asserts that Mr. Robert Brown has 
only developed his opinions, with this difference, that Mr. Brown 
thinks that in observing the motions of inorganic substances, he 
has established a new law ; while Mr. Raspail only sees in these 
phenomena, the most simple and most ordinary effects of a number 
of causes sufiiciently well known. 
In No. II. of the New Series of the Edinburgh Journal of Science, 
there are some ‘‘ additional remarks on active molecules,’ by Robert 
Brown, F.R.S. &c. &c. in which, after correcting the notion that 
he had stated the active particles to be animated, he states the re- 
sults of the enquiry as follows:— 
“* That extremely minute particles of solid matter, whether obtained from or- 
ganic or inorganic.substances, when suspended in pure water, or in some other 
aqueous fluids, exhibit motions for which I am unable to account, and which 
from their irregularity and seeming independence resemble in a remarkable de- 
gree the less rapid motions of some of the simplest animalcules of infusions. 
That the smallest moving particles observed, and which I have termed Active 
Molecules, appear to be spherical, or nearly so, and to be between 1-20,000dth 
and 1-30,000dth of an inch in diameter ; and that other particles of considera- 
bly greater and various size, and either of similar or of very different figure, also 
present analogous motions in like circumstances, 
