acknowlege the merit.of a foreigner; and that, on the present
occasion, besides allowing all the due share of praise to the
immediate subject of his memoir, he takes occasion to render
justice to Scheele, Priestley, and others, who, about the same
period, were engaged in the same train of pursuits.
: The first Memoir in this department is by M. RICHARD,
On the Hydrocharides ; i. e. on the Plants which, with the
Hydrocharis, constitute the natural Family of this Name.
Our readers: must be aware of the fondness which the French
botanists manifest for the plan of forming natural families;
a plan which, if cautiously pursued, is well calculated to pro-
mote botanical science, but which, on many occasions, they
have certainly carried to an unreasonable extent. We will
not decide whether this remark applies to the case now be-
fore. us: but we are disposed to think that, although the
plants placed together, as forming one natural division, have
some common points of resemblance, they are very dissimilar
in many essential parts. The essay is extremely elaborate,
being extended through.88. 4to. pages; and indeed it seems to
contain every thing essential to the complete investigation of
the subject. The plants which are classed under the title of
the Hydrocharides are the Elodea Guyannensis, which is little
-known, and which grows in Guiana, as its specific name
imports'; the Anacharis Callitrichoides, which was discovered
by Commerson, near Monte Video'; Hydrilla ovalifolia, an

Indian plant described by Roxburgh; Vallisneria spiralis, an
· European diæcious plant; Blyxa Auberti, also a diæcious
plant, discovered by M. Aubert du Petit Thouars, at Mada-
gascar; Blyxa Roxburgi, a native of Coromandel;. Stratiotes
aloides, a well-known European plant; Ottelia Alismoides, an
inhabitant of the Nile, near Rosetta, and perhaps also of India;
Limnobium Bosci, a native of South Carolina, where it was
discovered by M. Bosc, after whom it is named; and, lastly,
the Hydrocharis Morsus-Rane, a common and well known in-
habitant of various parts of Europe, which on this account
gives its name to the whole family. After a minute :scientific
description of each of these plants individually, the author
-makcs some obserýations on the family generally, their habits,
their different parts, and their various organs. The charac-
ters are given in Latin, arranged into orders and genera; and
a conspectus of the whole is added, together with a series of
engravings. To the - memoir is subjoined a description, with
a figure, of the plant generally known in medicine under the

title of Angustura, but now named Bonplandia. ii
:: The next paper is a Continuation of M. GUYTON-MOR-
VEAU'S Essay on Pyrometry; the principal object of which is

5*...

to

In the succeeding article, the Secretary supplies notices of the lives of Malus and Lagrange ; of the latter of whom we have already spoken in our report of his Mécanique Analytique, and respecting the former we shall merely transcribe one sentence: Newton, speaking of a young friend whom he had lost, said, “ If Cotes had lived, we should have known something:” and we may, in like manner, say, If Malus had lived, he

would have completed the theory of light.' This celebrated philosopher, whose name will be transmitted to the end of time in consequence of his discovery of the polarization of light, died on the 24th of February 1812, in the 37th year of his age, and was replaced in the Institute by M. Poisson ; who is well worthy to succeed him.

(Part I.) MEMOIRS. - On a new Kind of Oscillation which the Particles of Light experience in traversing certain Crystals. By M. Brot.

(Part II.) On a new Application of the Theory of Oscillations of Light. By the Same.

On the Discovery of a new Property in the polarizing Forces of certain Crystals. By the Same.

On the Physical Properties that the Particles of Light acquire in traversing double refracting Crystals. By the Same.

These memoirs occupy more than 400 pages, and are crowded with numerous experiments and ingenious deductions; which, as we have before remarked in reference to this author's paper in the preceding volume, bid defiance to any intelligible condensation. We must consequently pass over them with the mere enumeration of their titles.

Result of the Meteorological Observations made at ClermontFerrand, from the Month of June 1806, to the End of 1813. By the Baron Ramond. — On examining the dates in the title to this memoir and the title of the volume itself, it will be found that the article which is here said to be inserted in the volume for 1812 was not written, and the experiments which it details were not finished, till 1813; that it was not read till 1814; and that it was not published till 1816. We cannot but remark the impropriety of thus giving an apparent earlier date to papers than the period at which they were written. Let us imagine such a case as the invention of fluxions by an Englishman in 1813, which is mentioned to a few friends, and arrives by some means at Paris in 1814; let us farther imagine a foreigner so lost to all sense of honour as to appropriate to himself that which he knows, and he almost exclusively, to belong to another; of which we will suppose him to present an account to the Institute in the latter end of this year; and the memoir to be then pubM m 4

lished