REVIEWS. 91 



jed;, to say the least of it, not calculated to engage the attention of boys, 

 and certainly, if at all properly handled, not level with their capacity. 

 One chapter we have on rocks, in which, as a matter of course, we are 

 told the difference of aqueous, igneous, and metamorphic rocks, but not a 

 word about a fossil not so much even as to lead the boy who reads of 

 geology to know what the great business of geology is namely, from the 

 exuvia of defunct species of animals and vegetables to trace out the ages, 

 groupings, and relative positions of the rocks which lie apparently in such 

 utter confusion on the earth's surface. 



Let us now return, no matter how unsatisfactory the task may be, and 

 examine whether this food provided for the sustenance and growth of the 

 youthful mind is merely insipid and innutritive, or whether it may not 

 contain some noxious ingredient whether, in fact, the baker has not put 

 alum or plaster of Paris in our bread. 



The author begins by cautioning his boy-reader against the exploded 

 error of the old philosophers, who taught the existence of four elements 

 earth, air, fire, and water ; and informs him that, in the present state of 

 chemical knowledge, we believe in upwards of sixty elementary bodies, 

 which he proceeds to classify. Our reader, perhaps, expects to find the 

 old-fashioned division of metalloids and metals, of the metals into alkalies, 

 alkaline earth, earths, &c. ; if so, he will be disappointed, perhaps not 

 justly. We all know the extreme difficulty which so frequently recurs in 

 the natural sciences of accurate and scientific division. We all know, for 

 instance, the doubt that is felt in placing magnesian with the alkaline 

 earths, rather than with the earths in considering arsenic as a metal, 

 rather than a metalloid, isomorphous with phosphorus. And if this be 

 so, why should not Mr. Jukes be allowed the privilege of proposing a new 

 classification ? His division is three-fold ; we quote his words " First of 

 all, there are all the pure metals such as gold, silver, iron, lead, copper, 

 tin, antimony, manganese, zinc, and a great many others which do not 

 ordinarily occur; secondly, there are six substances, called sulphur, phos- 

 phorus, carbon, silicon, boron, and selenium; and, lastly, there are seven 

 substances which, when pure, are always found in the state of gas, or 

 aeriform fluid ; these are called oxygen, hydrogen, nitrogen, iodine, 

 chlorine, bromine, and fluorine." 



We can readily conceive the astonishment of the chemist who reads this 

 page ; but for the sake of the general reader, and lest any mistake arise, 

 we shall enter into particulars. We are told that iodine, is a gas ; on 

 referring to " Turner's Chemistry," we find it described as " a soft, friable 

 opaque solid, of a bluish-black colour, and metallic lustre ; it occurs usually 



