Notices respecting New Books. 383 



found with absolute certainty, provided the data founded on ac- 

 tual experiment could be brought to perfect accuracy. Hitherto 

 however this has not been tlie case, as no series of numbers re- 

 presenting the neutral compounds has yet been given which will 

 applv throughout. It is a chief part of the present labours of 

 Prof. Berzelius to correct the elements of these calculations by 

 varied experiments conducted with great care and intelligence. 



" Another equallv important law laid down by Richter is, that 

 v/hen the metal of a neutral metallic solution is precipitated by 

 another metal, it is the metallic base alone which is changed, 

 the oxvgen and the acid remaining united with the last added 

 metal. Hence it follows that all the different metallic oxyds 

 wliich saturate a definite portion of acid contain the same quan- 

 titv of oxygen. Or in other words it mav be expressed, that a 

 given quantitv of any acid combines to saturation with onlv a de- 

 finite proportion of oxvgen iniited to so much of any base as con- 

 tains this portion of oxygen. Thus for example, if 100 parts of 

 sulphuric acid saturate 20 parts of oxygen and the base united 

 with it, the proportion of every oxyd that combines with 100 of 

 sulphuric acid, and the composition of every neutral suJphat is 

 known as soon as the oxvd itself is analyzed. And, conversely, 

 the composition of anv unknown oxyd may be discovered by find- 

 ing the quantity of this oxvd v/hich neutralizes a given weight of 

 anv acid whose saturating quantity of oxvgen in any other oxyd 

 is previously known. Thus, for example, if 100 parts of sul- 

 phuric acid saturate any oxyd that contains 20 of oxygen, it mav 

 be inferred that 1 IG parts of potasii are composed of 20 of oxv- 

 gen and 95 of potassium, since this quantitv of potash saturates 

 100 of sulphuric acid. The like quantity of oxvgen is therefore 

 contained in 7S of soda, in 190 of barytes, ike. &c. each of 

 which saturate 100 of sulphuric acid. 



" The late discovery of the compound nature of the alkalies 

 and earths, therefore, gives an additional importance to this law 

 of chemical affinity. 



" Another law of chemical combination, which is laid down 

 by Berzelius, and illustrated by numerous examples, is the fol- 

 lowing: viz. In any compound of two oxvdated substances, that 

 substance which is attracted to the positive pole of the electric 

 circuit (tlie acid, for example,) contains as much oxvgen as is 

 produced l)v nniltiplying the oxygen of the substance attracted 

 to the negative pole (sucli as alkali, earth, metallic oxyd,) by 

 some of the intei/ral numi)ers 2, 3, 4, 5, &c. For example, 

 as iOO |)arts of suljihuric acid saturate as much of any oxyd 

 a« co!it;iins about 20 parts of oxygen, the quantity of oxygen 

 in 100 parts of the acid itself must be equal to twice 20, or 

 tliree times 20, &c. In this example it will be shown presently 



that 



