59 
D. Temperature 100° C. 
Weight of liquid in bulb 4 ’9 9 6 5. 
Weight of residue on evaporation 0'7870. 
Specific gravity of aqueous solution saturated at 100°, 
1-06603. 
Percentage of salt in solution 15 ’7 6. 
Solubility, 1 partin 5 04 of water. 
For each rise of 25° the solubility and the percentage of 
salt in solution increase in round numbers threefold. 
I may add that I found Hannay’s apparatus exceedingly 
accurate and serviceable. 
II. On Basic Bismuth Perchlorate. 
If metallic Bismuth be heated with an aqueous solution 
of perchloric acid it is slowly converted into a white non- 
crystalline mass. This substance is insoluble in water; 
when thoroughly washed and dried between folds of blot- 
ting paper it presents the appearance of a bulky, pure white 
powder which it is difficult to obtain equally divided as the 
particles tend to gather together and form small more or 
less compact masses. This substance yields the following 
numbers on analysis : 
(a) 0-364 grams gave 0*2675 grams Bi 2 0 3 = 0-2382 grams JBi. 
(5) 0-4173 
v n 0-298 ,, )) 
= 0-267 
a ii 
(c) 0-450 
n ii 0”3231 j, „ 
= 0*290 
)i a 
Calculated for BiO.C10 4 
Found. 
I. II. 
III. 
Bismuth 210 
64-52 
65-44 63-98 
64-44 
These numbers agree very well with those required by 
the formula BiO.C10 4 , or it may be written Bi(C10 4 ) 3 .Bi 2 0 3 . 
Basic Bismuth perchlorate is almost perfectly insoluble in 
water even at 100°; it is very readily dissolved by hydro- 
chloric or nitric acid ; less readily by sulphuric acid ; at a 
red heat it is decomposed with formation of bismuth 
chloride which is slowly volatilised. 
