3o6 HISTORICAL INTRODUCTION TO CHEMISTRY CHAP. 



necessary to convert this quantity into oxalate be x, then 

 2X will convert it into superoxalate." 



" It appears that there are two oxalates of strontian. . . . 

 It is remarkable that the first contains just double the pro- 

 portion of base contained in the second ;> (A.C.R. II. 41). 



In a paper (A.C.R. II. 34-40) read before the Royal 

 Society on Jan. 28, 1808, a fortnight after Thomson's, 

 William Hyde Wollaston, the Secretary, showed that a third 

 oxalate of potash existed, the relative quantities of acid in 

 the three salts being in the ratio 1:2:4. He also showed 

 that in the two series of CARBONATES the quantities of gas 

 were in the ratio i : 2, since 4 grains of the bicarbonate, 1 

 when converted into the carbonate by heating it, lost the 

 same amount of gas as 2 grains of the same salt when 

 wholly decomposed by acid ; these observations are com- 

 firmatory of those made 40 years before by Cavendish 

 (p. 69). Again, in the case of the SULPHATES, Wollaston 

 found that "super-sulphate 1 of potash may be shown to con- 

 tain exactly twice as much acid as is necessary for the mere 

 saturation of the alkali present." 



The gases which supplied Dalton with illustrations of the 

 law of multiple proportions were studied much more care- 

 fully by Gay-Lussac, who in his paper on the combining 

 volumes of gases (1809) quoted additional cases and pro- 

 vided more exact data, all tending to uphold the validity of 

 the law (see below, pp. 331-335). 



The law of multiple proportions stated and proved by 

 Berzelius (1810). One of the first chemists to feel 

 the fascination of the new problem of chemical pro- 

 portions was Berzelius, who published in 1810 a 

 "Research, to determine the fixed and simple Propor- 

 tions, in which the Constituents of inorganic Nature 



1 Wollaston speaks of sub-carbonate (= carbonate) and carbonate 

 ( = bicarbonate) ; sulphate and super-sulphate ( = bisulphate) ; oxalate, 

 binoxalate, and quadroxalate. 



