476 Literary Notices. 



is metallic. Palladium is especially effective in this Way. And 

 iron absorbs carbonic acid instill larger quantities than hydrogen — 

 a circumstance which seems to explain certain facts connected with 

 the manufacture of steel. These metals have no effect whatever on 

 either oxygen or nitrogen. The necessity for the liquifaction of 

 gases, previous to their passage through caoutchouc, is due to 

 certain peculiarities of that substance. Though it refuses to 

 transmit gases as such, it is very pervious to fluid. It will absorb 

 water to such an extent, as to become opaque ; and its pores are so 

 much opened by this fluid, that the latter will pass through, and be 

 evaporated at the other side. The pores, indeed, are visible under 

 the microscope. 



PROJECTILES AFFECTED BY THE EARTH'S ROTATION. The discovery 



of the effect of the earth's rotation on the path of a projectile is 

 not new; but the practical consideration of it has oaly recently 

 engaged attention. The flight of projectiles, from their imperfec- 

 tion, and that of the fire-arms then in use, was formerly so 

 uncertain, that the small deviation produced by the rotation of the 

 earth was considered unworthy of any attention. Such is not the 

 case at present ; and hence the subject has been of late carefully 

 studied. The deviation depends on the latitude : being greatest at 

 the poles, and zero at the equator. In our latitude a shell, about 

 twelve inches in diameter, with a range of four thousand yards, 

 would deviate to the extent of eight yards. The direction of 

 deviation is different in the different hemispheres ; in ours it is, 

 whatever the azimuth of the vertical plane in which the path of 

 the projectile lies, always to the right. A deviation is caused also 

 by the rifling ; and as this depends on the direction of the latter, it 

 may, according to ciicumstances, either augment, or, to a greater 

 or less extent, diminish that caused by the rotation of the earth. 

 In our latitude, with a Whitworth gun, half the deviation arises 

 from the earth's rotation ; a proper system of rifling would therefore 

 prevent any deviation whatever. But it must not be forgotten that 

 a rifle without any deviation in one hemisphere would have a very 

 considerable one in the other : as it would become equal to the sum. 

 of the deviations caused by both the rifling and by the earths 

 rotation. 



LITERARY NOTICES. 



BENEDICITE; 01?, THE SONG OF THE THREE CHILDREN. Being illus- 

 trations of the Power, Wisdom, and Goodness of God, as 

 manifested in his Works. By G. Chaplin Child, M.D. In two 

 Volumes. (Murray.) — The canticle known as the " Benedieitc," 

 and commencing " Oh all ye works of the Lord, bless ye the Lord : 

 praise him and magnify him for ever," supplies Dr. Chaplin Child 

 with a series of texts on which he has written elegant lit tie disser- 

 tations of a scientific character.: The book is beautifully got up, 



