118 Chronicles of Science. [Jan. 
shown that the alkaloid brucine is a most delicate test for nitric acid, 
being coloured rose-red by water, containing only the 100,000th part. 
It is to be hoped that more attention will in future be paid to the 
varying proportions of this acid in potable water, and that the warn- 
ings given by its presence will not be disregarded. 
The subject of pure water for household purposes is so important 
that we again recur to it, to notice an invention of Dr. H. Schwartz, 
which appears to remedy perfectly the effects of the employment of 
lead pipes and cisterns. He converts the inner surface of the metal 
into an insoluble sulphide by boiling in it a solution of sulphur in 
soda. The result is that the water is perfectly kept from contact with 
the metal, and will be as free from contamination as if it had been 
passed through a glass pipe. 
Some curious results of the inhalation of the vapour of glonoine 
(an oil obtained by the action of nitric acid on glycerine) have been 
given by Mr. Merrick.* It has long been known that this body pro- 
duces violent headache, but these experiments show that it is a most 
powerful agent in its physiological action. In one case the fortieth 
part of a drop dissolved in spirit was swallowed on a piece of sugar. 
In two minutes the pulse had risen considerably, being accompanied 
with a violent headache. This continued for nearly half-an-hour, 
when the symptoms passed off. At another time, when a quantity of 
vapour was accidentally inhaled, the headache became almost intolerable, 
and was accompanied by a good deal of faintness and exhaustion, in- 
tolerance of light, and a feeling of great general distress and alarm. 
The violent toxical effects show that glonoine is a powerful poison, 
and, like most agents of this kind, will doubtless be employed in 
medicine. 
The application of gun-cotton as a substitute for gunpowder in 
warfare has occupied the attention of a committee of scientific men 
for some time past. General Von Lenk, of the Imperial Austrian 
Artillery, has invented a system of preparation by which gun-cotton 
has been made practically available for warlike purposes. The 
committee have had the advantage of personal communication with 
the General, and in the report, which will shortly be issued, an ab- 
stract of which having been communicated to the British Association at 
Newcastle, we are promised a vast amount of information of the most 
important character. General Von Lenk has shown that perfect gun- 
cotton is a definite chemical compound; he has given accurate pro- 
cesses for its manufacture, and for the removal of all extraneous matter 
and traces of free acid. As thus prepared, it is no longer liable to 
spontaneous combustion, it can be stored for any length of time with- 
out deterioration, it is not impaired by damp, and may be immersed in 
water without injury, its original qualities returning unchanged when 
allowed to dry in the air. These are valuable properties, and when 
we add to them the absence of smoke, the entire freedom from foul- 
ing, the innocuous character of the products of combustion in com- 
* “Silliman’s Journal,’ yol. xxxvi. No. 107. 
