420 Scientific Intelligence. 
a. Pure freshly precipitated sulphate of strontia was digested in the 
cold for two days with dilute sulphuric acid of spec. grav. 4°8. 150 grams 
of the filtrate left 0°3451 gram, so that 1 part dissolved 435 parts. Ina 
second experiment the proportion was 1 : 429. e average is 1 : 432 
b. Another portion of sulphate of strontia was digested in the cold for 
two days with dilute muriatic acid of spec. grav. 8°5. 100 grams left 
02115, and another 100 grams 0°2104 gram. The average solubility of 
sulphate of strontia in muriatic acid of the above strength is therefore 
expressed by the proportion 1: 474. 
c. A third portion was digested in the cold for two days with pure di- 
lute acetic acid containing 15°6 per cent of hydrated acetic acid, 100 
grams of the filtrate left 0°0126-and 0°0129 gram. ‘This gives the aver- 
78 
—s 
iron; it then becomes slippery and gelatinous, and at last furnishes 4 
brownish yellow solution. 
if the silk fibres be washed with water in the first stage of their _ 
in 
Solutions of alkaline salts do not precipitate the solution of silk, nor 
own of sugar and gum. It is remarkable that a solution 
jon for. several 
and there was no trace either.of swelling or coloration. Po 
also did not swell up in it; inuline was ually dissolved. hie 
- No analogous n has yet been produced upon silk by means ih 
oman of CoO, ZnO, and Al203 in NH3, In the coloration, swellP&s 
and solution of silk by NiO, it is essentially a matter ot} br 
whether the silk employed. be raw silk, or silk deprived of its dressing! 
wa! ee 
