384- Notices respecting New Books. 



The combining proportio7i of carbonic oxide is therefore 14-, and that 

 of carbonic acid 22. The italics are ours ; and we use them to mark 

 the circumstance that three different terms are used in the space of 

 as many lines, to express the same meaning. In p. 215, a similar 

 case occurs. 



In p. 217, the sulphuric acid obtained by decomposing sulphate 

 of iron is stated to be colourless : the fact is well known to be other- 

 wise ; but we believe the cause of the dark colour has not been 

 ascertained : Dr. Thomson, if we remember right, suspects that it 

 may be derived from the presence of selenium. 



We proceed now to the Metals, the arrangement of which, if we 

 may use the expression, is too chemical, and not sufficiently depend- 

 ent upon obvious or physical properties. The metals are divided into 

 two classes ; First, those the oxides of which cannot be reduced to 

 the metallic state by the sole action of heat ; Secondly, those metals 

 the oxides of which are reducible by heat only. As however the 

 metals of the first class are divided into four orders, the arrange- 

 ment is in fact equivalent to five classes. The first order includes 

 the metals which decompose water at common temperatures ; these 

 are stated to be six, viz. Potassium, Sodium, Lithium, Barium, Stron- 

 tium, and Calcium. Now to those ought to be added. Magnesium 

 from the second order, and Zinc and Manganese from the third order. 

 That the two former metals decompose water at common tempera- 

 ture, is stated by Davy. The action of manganese we have witnessed. 



The second order of metals includes Magnesium, Glucinum, Yt- 

 trium, Aluminum, Zirconium, and Silicium. 



One of the characteristics of these metals is stated to be, that 

 their oxides are very sparingly soluble in water ; but on referring 

 to the account given of each of them, three of them, viz. alumina, 

 glucina, and zirconia, are stated by Dr. Turner himself, to be 

 " quite insoluble in water;" and the same n)ight also have been men- 

 tioned with respect to yttria. The late experiments of Berzelius 

 have nearly demonstrated that neither silicium nor zirconium has 

 any claims to be considered as metals : indeed two circumstances 

 mentioned by Dr. Turner with respect to silicium, — viz., that it is 

 a non-conductor of electricity,and has no metallic lustre, — are almost 

 decisive with respect to that substance. 



The third order includes those metals which decompose water at 

 a red heat ; they are stated to be Manganese, Zinc, Iron, Tin, and 

 Cadmium. Now, as already noticed, two of these decompose water 

 at common temperatures; and according to Davy, antimony pro- 

 duces the same effect at a red heat. The remaining order includes 

 metals which do not decompose water at any temperature ; and the 

 second class contains those, the oxides of which are decomposed 

 at a red heat. 



From the length to which our observations have already extend- 

 ed, we shall be unable to allot more than a very limited space to 

 the remaining parts of Dr. Turner's work. AVe may however ob- 

 serve, that his account of the crystalline form of muriate ofbarytes 

 will, we think, justify an observation wehave previously made respect- 

 ing the little attention which Dr. Turner has paid to the subject of 



crystalizatioD. 



