Notices respecting New Books. 59 



tion on the celebrated discovery of Black is advanced is most amusing. 

 Speaking of the polarization of heat, our author remarks, " It may 

 be described, in general terms, as a power of turning the ray of heat 

 half round ; and it is regarded as proving that the influence of lateral 

 vibrations are different from the onward waves in calorific propul- 

 sion." If Mr. Hunt were compelled to write this nonsense, we 

 should pity him ; but it is his own free act, and we are therefore 

 disposed to be angry with him. What follows, however, is still 

 worse. In page 382 we are told, '* In the centre of the cornea 

 is a circular opening, the pupil, and within it is the crystalline lens 

 containing the vitreous humour." We entreat Mr. Hunt to think 

 once more. Is there an opening in the cornea ? Does the crystal- 

 line lens contain the vitreous humour ? With a very slight expen- 

 diture of trouble, Mr. Hunt might have informed himself on this 

 important subject, and thus spared us the pain of exposing his reck- 

 less inaccuracy. He has only to look into the eyes of his neighbour, 

 or his cat, to convince him of at least a portion of his error. 



In page 391 we find the following: — "A very simple con- 

 trivance, by which the relative illuminating powers may be ascer- 

 tained, is to allow the shadows from a single object to fall upon 

 a screen, and then remove the sources of light from or towards 

 it until all the shadows are of the same depth ; the distances 

 at which the illuminating bodies are from the screen express the 

 relative intensity of the light of each." Count Rumford would 

 never agree to this ; he would have said the squares of the distances. 

 In the next page we find the following piece of information : — "By 

 aberration is meant the difference between the real and the apparent 

 place of the stars. As the light is proceeding from them, the earth 

 is moving onward ; consequently they appear to be rather more 

 backward than they really are in the direction of the earth's annual 

 motion." This passage is suggestive of the scientific standing of its 

 writer ; it is the production of an amateur, who abides by first im- 

 pressions, and gives himself no further trouble. The effect of aberra- 

 tion is precisely the reverse of what our author states it to be. The 

 star from which the ray comes appears more forward than it really 

 is in the direction of the earth's annual motion. 



These are not superficial errors which might be attributed to im- 

 prudent haste ; they are cases in which general vagueness, confu- 

 sion, and ignorance of the subject handled, blossom out into palpable 

 absurdity. Did the book contain excellences, we should be glad to 

 bring them forward ; but it is obscure and unphilosophic through- 

 out. Even a quotation, in Mr. Hunt's hands, is not safe ; his state- 

 ment of the law of Newton, for example, in page 46, puts that law in 

 a dubious light. Had we not known something of the subject before- 

 hand, we should have derived but little enlightenment from the fol- 

 lowing : — "The distance from the middle point of a magnet being 

 the same, the force opposite the poles, or in the direction of the axis, 

 is double the force in the magnetic equator." . ..." In all cases the 

 south pole of a magnet will be found weaker than the north pole!" .... 

 " All bodies, such as glass, which allow magnetism to permeate them 



