SCIENTIFIC SUMMARY. 
203 
After first briefly referring to the observations of Reaumur (150 years ago) 
and to the later researches made on the devitrification of glass by Dumas, 
Pelouze, Terreil, and others, he gives a detailed account of his experiments 
and analysis of different kinds of glass before and after the devitrification. 
He concludes this very exhaustive essay by stating that, in his opinion, the 
behaviour of glass before and after devitrification is, that the silica in glass is 
not so much in the condition of three- or four-fold combination as in that of 
solution in glass (perhaps R0,2Si0 2 ), and then, as is the analogous case 
with all solutions to different temperatures, correspond different maxima of 
dissolved substance. 
Does Dilution cause a Precipitate from a Nitric Acid Solution of Gold % — 
This question has been long answered affirmatively, but Mr. A. H. Allen 
denies it. He states that [“ Chemical News,” .February 23] he prepared 
some pure auric oxide by precipitating a solution of gold in aqua regia with 
considerable excess of magnesia, boiling, washing with hot water till the 
washings were perfectly free from chloride, dissolving the precipitate in 
dilute nitric acid, boiling and washing till the water no longer reddened 
litmus. The auric oxide so obtained was heated with strong nitric acid, in 
which it is well known to be soluble, all authorities stating that dilution 
causes the complete precipitation of the gold as auric oxide. This he does 
not find to be the case, a perfectly clear and nearly colourless solution being 
obtained on dilution, in which the gold must evidently be present as nitrate, 
as argentic nitrate gives no trace of precipitate, and no other salt radical is 
present. The solution of auric nitrate answers to the ordinary tests for gold, 
and is but gradually decomposed, with deposition of auric oxide having the 
same properties as before. The decomposition is more rapid when the liquid 
is heated. 
A New Dye Stuff. — In the “ American J ournal of Pharmacy ” [February 
1872], Dr. J. Merrick speaks of flavine, also sold under the name of 
aurantine, and which, according to reliable information, is a preparation of 
quercitron bark, well known in Europe, and manufactured in the United 
States by a process kept secret. According to the researches made by Drs. 
Bolley, Brunner, and Konig, flavine is sometimes nearly pure quercitrine, 
sometimes quercetine, and usually a mixture of the two. By dissolving the 
dye-material contained in quercitron bark in an alkaline solution, and next 
treating it with sulphuric acid, Hochstaetter and Oehler have obtained a 
flavine-like substance. 
Chondrine in the Tunicata. — According to Dr. Schafer’s researches, these 
low mollusks contain in their tissues a substance which in its properties and 
percentage of nitrogen corresponds closely to chondrine , which is essentially 
a vertebrate type of substance. This is another fact in favour of those who 
bring the vertebrates from the Tunicate class. 
Artificial Coniine. — Some further researches have been made on this 
subject. In the second number of the Proceedings of the Chemical Society 
of Berlin, Herr Schiff commences a paper with' the detailed description of 
the method of preparation of coniine by artificial means, starting with 
butyraldehyde exposed to direct sunlight for several months along with 
alcoholic ammonia solution kept in a well-stoppered bottle. The artificially- 
obtained alkaloid is, as regards its physiological action, akin to the natural 
