W. Gibbs— Complex Inorganic Acids. 61 
1877. Mean C; App. App. Decl. No. of Comp. 
May 3. | 11" 235), — - 80° ia 6 
ae F 56 31 paris * mn 2’ 29°07 4 
M4, 510 ~ B.- .6:4.5%) 26" 26°08 5 4-60°-9".25¢1 8 
“ 5.110 10 88/15 15 50°04 59 30 24°7 8 
“12.110 6 41/6 29 25:59 BA Fe Bi 10 
*30.1. 0-58 dt 1848 1°60 ites 45 34°3 10 
_Tefractor. All the other observations were obtained by myself 
with the filar micrometer of the 133 inch refractor, using a power 
of 270, and illuminated wires. 
Comet III had always a more or less blurred aspect, without 
oe nucleus, paces the pointing difficult. 
n, N. Y., June 1, 
Arr. X.— On Complex Inorganic Acids. From a letter of Dr. 
va Grsss to one of the Editors, dated Cambridge, June 
th, 1877, 
oo, acid. ‘The two first mentioned are src or 
metameric, and de We on an es the formulas: 
Si0,. 40H,, or W, 203,Si(OH)., 
while the third bist he formula 
10WO, . SiO,. 40H, or erin 
It occurred to me that these results might be generalized in 
various Ways, and I have in fact obt see | _ very interesting 
new re of acids of the same or similar typ Platinic c hydrate 
PuOH H), boiled with an acid we tun bath  yickia two isomeric 
°F Metameric sodium salts which have the formula: 
LOWO, . PtO, . 40Na, +25 aq. 
