304 I.hisical Temperament of Keyed Iiistruvients. 



D. Posidve unipolar. — The Galvanic circle is nol closed ; 

 the substance applied to tlie two poles, only conducts the 

 positive effect and isolates the negative; whence results the 

 charge of the negative, and the impossibility of charging 

 the positive. 



This faculty belongs to the flame of hydrogen gas, and to 

 that of the hydrocarbonatcd bodies. 



E, Ncgalive imJpolar. — The Galvanic circle is not closed; 

 the substance applied to the two poles isolates the positive 

 effect and conducts the negative effects. Its contact charges 

 the posiilve exclusively, and adds nothing to the negative. 

 This class is composed of the Jiame of phosphorus and of 

 the alkaline soaps. 



_ ^^ - 



XLII. On the IMiisical Temperament of Keyed Instruments, 

 By William Hawkes, Esq. 



To Mr. TiUoch. 



i. ORSERVED in the Monthly Magazine of September 1£06, 

 some critical renjarks on earl Stanhope's Method of tuning 

 Keyed Instruments ; I have also seen Mr. Farcy's calcula- 

 tions and his philosophical disquisitions in your Magazines 

 of April and May last on the subjt-ct ; but they are not suffi- 

 ciently satisfactory to induct; me to alter mv opinion of the 

 method I published in 18U5, prior to earl Stanhope's. I 

 think the principle upon which the noble earl has acted is 

 very ino'enious, and I sincerely wish his lordship had suc- 

 ceeded in his endeavour to give a better effect to the instru- 

 ment by his means of dividing the enharmonic difference 

 of those tones which in extended modulation (from the im- 

 perfection of the instrument) become substitutes for real 

 ones, and which inevitably produce those disgusting chords 

 termed wolves by some. It is to be lamented there are such 

 insurmountable difficulties in melodizing or sofV-ning those 

 tones; indeed, I despair of ever hearing tolerable harmony 

 throughout the twentv-four keys of the present scale; con- 

 sequently, conceive it to be impracticable, unless two scales, 



the 



