194 
so; + =. cu. When this body .is put into contact with 
water, sulphate of water is formed, and arseniuret of copper 
deposited ; this arseniuret being likewise at once precipi- 
tated, when arseniuret of hydrogen is passed into a solution 
of sulphate of copper. 
Dr. Kane found also, that when arseniuret of hydro- 
gen is passed over chloride of copper, chloride of hydrogen 
is set free, and the same arseniuret of copper is produced, 
2as _ 2as 
cl.cu + aH = “a om +clH. 
In examining the constitution of the alum, the analysis of 
which by Dr. Apjohn, was read to the Academy last winter, 
Dr. Kane found that the water had been estimated by that 
chemist a little too high; thus Dr. Apjohn gave 48,15, while 
the true quantity amounts to 47,60. This small variation, 
however, makes, according to Dr. Kane, an important dif- 
ference in the theory of the body, as the number of equiva- 
lents is reduced to 25 in place of 26: and Dr. Kane looks 
upon the salt as composed of — 
Sulphate of Manganese mno.so;.Ho + 6 HO. 
Sulphate of Alumina Al, 0; +380; + 18 Ho. 
(Mn 0.HO) S03 + (Al, 03 + 3803) +6 HO + 18 Ho. 
In a temperature of 212° this salt loses 18 Ho, and by 300° 
six of the remaining atoms. The twenty-fifth atom is retained 
up to 600°: and Dr. Kane looks upon this salt as a remarkable 
case of the replacement of amide of hydrogen by an oxide of 
the same class; he further stated that it was by this princi- 
ple he was led to the repetition of Dr. Apjohn’s analysis. 
Sir William Betham read a paper ‘‘ on Etruscan Hand 
Mirrors,” particularly that figured in Dempster’s posthumous 
work De Etruria Regali, Vol. I. Tab. I, p. 78, from the ori- 
ginal in the Cospian Museum at Bologna. 
