Analysis of several Varieties of Salt. 171 



Here the fifth d*A* beats 14 times, and the fourth 

 A*d* the same, and the third d*G beats 169 times. 



From the above comparisons of Mr. Smyth's table, with 

 the rules in this pamphlet, it will I think appear plain, that 

 the writer of them had no proper conception of the nature 

 of an equal temperament, and that it is extremely unlikely 

 that he had ever heard or calculated such a temperament, 

 decidedly as he speaks of his trials of it: and I fear, sir, 

 that this is no uncommon case, in the present rage for 

 writing principles of music, principles of tuning, theories 

 of harmonics, instructions for tuning, 8cc. &.c. by persons 

 who ought first to employ themselves, in studying the very 

 .elements of the science of harmonics. 



Among the recommendatory criticisms for different Re- 

 views, of the pamphlet before me, one for the Phil, Mag. 

 has been forgotten, which I suggest should have run thus : 



A careful examination of the instructions contained in this pamphlet, 

 for tuning an equal temperament, convinces us, that the assumed name 

 Musicus Ignoramus of its author, is no misnomer ; and that the wit dis- 

 played therein, vastly exceeds its science, or its usefulness. 



I beg pardon for obtruding so long a letter on your at- 

 tention, and am, sir, 

 August 6, i8io. Yours, &c. &c. &c. 



XXXTf. An Analysis of several Varieties of British and 

 Foreign Salt, (Muriate of Soda,) with a vieiv to ex- 

 plain their Fitness for different oeconomical Purposes. By 

 William Henry, M.D. F.R.S. Vice-Pres. of the Li- 

 terary and Philosophical Society, and Physician to the 

 Infirmary, at Manchester. 



[Concluded from p. 119.] 



Sect. III. Account of the Methods of analysing ike se- 

 veral Varieties of Muriate of Soda. 



JL he method of analysis which I adopted, in examining 

 the several varieties of muriate of soda, was as follows. 



When the salt was in a state of solution, a measured 

 quantity was evaporated to dryness in a sand heat, which 

 was carefully regulated, to avoid the decomposition of the 

 muriate of magnesia, if any of that salt were present in the 

 solution *. 



• Muriate of magne'sia, according to Dr. Marcet, begins to part with its 

 acid at a temperature a few degrees above that of boiling water. This fact 

 explains the observation of Mr. Kirwan, that too great a heat, employed in 

 the desiccation of muriate of magnesia, decreases considerably its solubility 

 in alcohol. (Kirwan on Mineral Waters, p. 215.) 



Each 



