NOTES AND ABSTRACTS IN CHEMISTRY AND PHARMACY. 
293 
in the warm. It deviates the plane of polarization to the right like cinchonine, 
but to a less extent. It forms a chloroplatinate, crystallizing in long needles 
soluble in hydrochloric acid. It reduces nitrate of silver in the warm, and in 
the cold gives a white precipitate. 
Carboxycinchonic Acid. —This compound, which contains C 21 H J4 !N' 2 0 4 , 
results not only from oxidation, but also from a fixation of carbon; its forma¬ 
tion appears to take place when the disengagement of carbonic acid is energetic ; 
the quantity obtained is small. The acid is very soluble in water, and it crystal¬ 
lizes in hard anhydrous prisms, at first transparent, but becoming opaque. 
Strong alcohol dissolves about 1*8 per cent, in the cold, and 3 per cent, when 
boiling. Its action on polarized light is null. It is a bibasic acid, forming with 
the alkalies and baryta very soluble, badly-crystallized salts. The baryta salt 
contains C 21 H 12 TsT 2 0 4 Ba. The copper salt forms at first a pale green amor¬ 
phous precipitate, but rapidly becomes crystalline and of a deep blue colour. 
The silver salt, C 21 H 12 IL 2 0 4 Ag 2 , forms a very stable crystalline precipitate. 
This acid also dissolves in hydrochloric acid, and furnishes a crystalline chlo¬ 
roplatinate. 
Soluble Albumen. 
Large quantities of dried albumen, prepared from eggs and also from the 
serum of blood, are employed in the arts to fix the colours upon dyed fabrics. 
It is well known that considerable variation occurs in the coagulable power of 
different commercial samples of such albumen. This is sometimes attributed to 
adulteration. 
M. Monnier, pharmacien at Nyon, has published the results of a number of 
experiments upon this subject, from which it appears that the coagulable power 
of albumen is materially affected by the influence of sunlight during the process 
of drying. He found that white of egg evaporated in the sun in an open dish 
yielded a product which did not coagulate by heat ; but if the evaporation was 
conducted rapidly in a stove by diffused light only, a coagulable product was 
obtained. He has also ascertained that the addition of a small quantity of 
acetic, formic, tartaric, or citric acid in very dilute solution to the incoagulable 
albumen produces no precipitate, but restores the property of coagulating by 
heat like fresh white of egg. 
Preparation of Nitrogen. 
An Italian chemist, M. Levy, has indicated a new method of preparing 
nitrogen gas. The process he suggests is to heat bichromate of ammonia in a 
retort; it is decomposed into green sesquioxide of chromium, watery vapour, 
and nitrogen. 
(N H 4 ) 2 Cr 2 0 7 = Cr 2 0 3 -f 4H 2 O+N s 
New Reagent for Detecting Iron and Copper. 
M. Felix Bellamy has indicated a new reagent for detecting minute traces of 
iron or copper in natural waters. He states that an alcoholic tincture of log¬ 
wood constitutes a test for these metals of unrivalled sensibility. The hema¬ 
toxylin combines with either iron or copper, immediately producing a pure blue 
colour resembling that of the iodide of starch. The tincture is best prepared 
by macerating 12 or 15 parts of fresh thin shavings of logwood in 100 parts of 
alcohol. The alcohol should be previously purified by digestion on quicklime, 
and distillation from a glass retort. On adding a score of drops of this tincture 
to 200 cubic centimetres of water free from iron and copper, the liquid becomes 
yellow if carbonic acid predominates, or rose-violet if the earthy or alkaline bi¬ 
carbonates are present. If a clean iron wire be then introduced, the colour will 
be seen to change in the space of one or two minutes, blue stiise foiming round 
the metal and passing to the bottom. 
