SCIENTIFIC SUMMARY. 
89 
carbonate of ammonia, which is converted into bicarbonate by the excessive 
acid of the soda salt. No sulphur or sulphuric acid is needed. The soda 
obtained is very strong, and free from sulphur compounds. Plant, fuel, and 
labour are economised, and the escape of noxious gases is at an end. (As 
soon as we see this system at work, we will examine its probable con- 
sequences — scientific, sanitary, and commercial, says the “ Chemical News.”) 
Cochineal Red on Cotton. — “Reimanns Farber Zeitung” says that this is done 
as follows : — To 10 lbs. of goods take 10 ozs. of tannin, and dissolve it com- 
pletely in boiling water. Lay the goods overnight in the solution. Pre- 
pare some red liquor at 12° Baume, and put into a small tub a sufficient 
quantity to work 2 lbs. of cotton yarn. Work the yarn for ten minutes. 
Fill up the red liquor to its original quantity, and work 2 lbs. more ; and 
so on, till the whole of the yarn has been mordanted ; it is then allowed to 
dry, with frequent turning. Piece-goods are winced for an hour in red 
liquor of the same strength. When dry, the goods are passed through a 
boiling bath of 1 lb. of prepared chalk to every 10 lbs. of cotton, and washed 
twice. 1 to ltj lb. of cochineal is boiled out in water ; a coloul--bath is 
made up at 40° Reaumur, with the addition of a little flavin, and the goods 
are worked, raising the temperature slowly to near the boiling-point. 
No. 85, 1873. 
Modifications of the Cinchona Alkaloids and their Optical Qualities. — At 
the meeting of the Chemical Society, Nov. 6, Mr. D. Howard read a 
paper on this subject. After enumerating the various observations that 
had been already made, he drew attention to the approximate relation 
between the deviation caused by quinicin and cinchonicin and the alka- 
loids from which they are derived ; thus the mean of the specific rotary 
power of quinine and quinidin in alcoholic solution is 47° to the right, and 
that of quincin, corrected for its combined water, 41°, whilst, in aqueous 
sulphuric acid, they are 20-5° and 19-4° respectively. A similar approxima- 
tion is found to be the case with cinchonicin as compared with cinchonin 
and cinchonidin. The action of nascent hydrogen on the alkaloids in apid 
solution gives rise to compounds which Schutzenberger regards as differing 
from the original compound in containing one atom more water ; the author, 
however, is inclined to doubt this, as no evolution of hydrogen occurs when 
cinchonin or cinchonidin is treated with zinc and dilute sulphuric acid 
until a considerable excess of the acid has been added : the optical pro- 
perties of the bodies formed are very similar to those of quinicin and cin- 
chonicin. The author then proceeded to describe the method of preparation 
and optical properties of the various ethyl bases produced by the action of 
ethyl iodide or bromide on the cinchona alkaloids : the rotation produced 
by the salts of the ethyl bases is in most cases very nearly proportional to 
that which would be given by a salt of the original alkaloid, equal in 
amount to that contained in the new compound. 
GEOLOGY AND PALAEONTOLOGY. 
Darwinian Doctrines among Geologists. — Mr. Henry Woodward, F.R.S., 
F.G.S., has just published, in the “ Geological Magazine ” for December, the 
