Notes. 
1879.] 
707 
advanced classes ? What authority is weighty enough to settle 
the existence or non-existence of these bodies ? 
At a meeting of the Academy of Sciences, on September 1st, 
M. P. T. Cleve announced the discovery of two new elements in 
erbia, which he has named respectively Thullium and Holmium. 
Herr Fleitmann conceived the idea that the brittleness of 
nickel and cobalt was due to absorption of carbonic oxide. He 
succeeded in removing it by the addition of small quantities of 
magnesium, obtaining both metals in a perfectly malleable and 
duCtile condition. To prevent explosions, the magnesium is 
mtroduced through a hole in the lid of the crucible after the 
oxygen has been removed by the addition of fragments of 
charcoal. 
A new method for the detection of arsenic has been devised by 
Prof. Selmi. The method is that of Schneider modified so as to 
incur no losses. The substance to be examined is treated with 
hot concentrated sulphuric acid, and during the same time is 
traversed by a current of hydrochloric acid gas, which carries 
with it all the arsenic in a state of chloride, separating it from 
the organic substances with which it was mixed. The arsenical 
liquid is then placed in a Marsh’s apparatus and tested in the 
usual manner. Prof. Selmi has been thus able to obtain the 
metallic ring on operating upon 100 gms. of animal matter con- 
taining 1 -400th of a milligrm. of arsenious anhydride. 
Reichenbach’s wood-tar colour Pittical has been resuscitated 
by A. Gratzel, and it is now an article of commerce at the price 
of £4 per kilo., under the name of “ German-Imperial-Flower- 
Blue,” with reference probably to the blue corn-flower, which is 
said to be the favourite cognizance of the German Emperor. 
The acetate is generally used for dyeing, dissolved in a little 
acetic acid diluted with water, and almost neutralised with 
ammonia. In this bath silk and wool take a fine reddish blue 
without the aid of any mordant. Cotton and other vegetable 
fibres are prepared with a solution of tannin, followed by a solu- 
tion of tartar emetic. The colours produced are perfectly fast. 
From Reimann’s “ Farber Zeitung ” we learn that if Pittical is 
separated from its alkaline salts, and heated with alcoholic 
ammonia in a sealed tube to 176°, a base is obtained closely 
resembling rosanilin in its composition. It dissolves in acetic 
acid with a corn-flower blue colour. The new colour is the first 
member of a new series of tinctorial products, which may prove 
of great importance. 
Dr. Meusel, of Breslau, prepares colouring matter by treating 
coal-dust with nitric acid, or with a mixture of alkaline 
nitrates and sulphuric acid, or with other oxidising agents. A 
part of the coal is thus rendered soluble with a deep brown 
colour in alkaline hydrates or carbonates. The black residue 
serves as a body colour. The brown alkaline solution can (says 
