206 Miscellanies. 
particular kind of compound, to which they gave the name of ammo- 
niacal azoturet of potassium; although this name expresses a partic- 
ular mode of combination, still, the experiments of the French chem- 
ists do not determine, with sufficient exactness, the elementary com- 
position of this substance, especially, as these experiments, when re- 
peated by Davy, furnished different results. 
New experiments, conducted with all the precision sidlediin to 
the present state of the science, are demanded, in relation to the am- 
moniacal azoturet of potassium. These experiments should be pre- 
faced by an exposé of those of Gay-Lussac and Thenard and of 
Davy. References should also be had to what is stated on this sub- 
ject in the second volume of the French edition of Berzelius’s Chem- 
a 
The authors of the memoir, after having determined with precision, 
the elementary composition of the subject of his experiment, will try 
to elucidate the mode of combination which appears most probable 
to express the nature of the substance analyzed. 
The pieces should be sealed and they may be written in Russian; 
German, French or Latin, and addressed to the perpetual secretary 
of the Academy, before the first of August, 1834. The prize of one 
hundred Dutch Ducats, will be decreed in the public sitting, to be 
held.on the 29th of December of the same year. The successful 
piece will be printed at the expense of the Academy.’ 
21. Dr. Young’s Elements of Geometry, &c. §c.—* The Ele- 
ments of Geometry ,”—‘ The Elements of the Differential Calculus,” 
—and “The Elements of the Integral Calculus,” by Dr. Young, 
have been presented to the public by Carey, Lea and Blanchard, in 
three octavo volumes. They are designed for the use of Colleges 
and Universities, and contain full — expositions of the ‘sub- 
jects of which they treat. 
It is the author’s plan to give a haga and more comprehensive 
view of Geometry, than has been done by any preceding geometer 5 
and it is his aim to adhere to that accuracy of reasoning, and rigor of 
proof, in his geometrical investigations, which shall not leave conclu- 
sions “ only approximately true,” but shall establish every proposi- 
tion by demonstrating the converse where demonstration is possible, 
pointing out ‘‘ those cases where it necessarily fails.” This mode of 
proceeding must be highly satisfactory to the learner, who thus not 
only ascertains, that “ under certain conditions a certain property 
