Technical Chemistry. 429 
metals of the group appear to be all soluble, The ruthenium salt is 
beautiful reactions with sulphocyanid of potassium and sulphydric acid 
are much inferior for qualitative purposes.” 
New York, March 30, 1860. 
AL STRY. 
9. Solution of Cellulose in Ammonio-oryd of copper—Some time since 
ERMany, in his Journal fiir praktische Chemie (\xxvi, 386) expressed the 
opinion that cellulose is not really dissolved by cuprate of ammonia, as 
-stated by Scuwerzer (ibid, Ixxii, 109), but only swollen to a sort of thin 
mucilage like the well known limpid “ solution” of starch. 
This view was based upon the fact that when a clear solution of cellu- 
lose in NHz CuO is diluted with a large excess of water, the cellulose 
separates entirely in the course of a few days. 
In defense of his original statement Schweizer now urges that the 
of water ;—hydrate of copper bein recipitated. : 
is Sebiits oaks tthe which ‘water exerts upon solutions of the 
compound of ammonia and oxyd of copper is in the opinion of Schweizer 
a cause of the gradual precipitation of cellulose from such solutions 
When these are largely diluted.—Journal fur praktische Chemie, \xxviii, 
870; compare also Cramer, ibid. Ixxiii, 1, e¢ se 
completely destroyed. The same thing occurs with a number of other 
Coloring matters.—In noticing this fact BarREswit suggests that persul- 
‘yas 
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