236 Scientific Intelligence. 
SCIENTIFIC INTELLIGENCE. 
I. CHEMISTRY AND PHYSICS. 
1. On the production of Fluorine by the electrolysis of Hydro- 
gen Fluoride.—In June last, Motssan communicated to the French 
Academy the results which he had obtained by submitting liquid 
hydrogen ffuoride to electrolysis. The anhydrous liquid was 
contained in a V-tube of platinum cooled to —50°, and the current 
needed was supplied by 50 Bunsen cells. Hydrogen was evolved 
at the negative electrode, and there appeared at the positive 
electrode a gas having the following properties: In contact with 
mercury it was completely absorbed, forming yellow mercurous 
fluoride; with water, it formed ozone; phosphorus spontaneously 
inflamed in it, forming phosphorus fluorides; sulphur heated and 
melted; carbon had no action; fused potassium chloride was 
attacked in the cold, evolving chlorine; crystallized silicium, 
carefully purified, took fire in the gas, producing silicium fluoride. 
The positive electrode of platinum-iridium was corroded, while 
the negative electrode of platinum was not affected. 
In a second paper, the author gives the details of subsequent 
experiments. The hydrogen fluoride was obtained pure and 
anhydrous by heating hydrogen-potassium fluoride in a platinum 
alembic, and collecting the product in a platinum receiver 
immersed in ice and salt. In this way a colorless liquid was 
obtained, boiling at 19°5°, very hygroscopic and fuming strongly 
in the air. The platinum V-tube used for the electrolysis carried 
a small evolution tube near the top of each limb. Its ends were 
closed by stoppers of fluorite, through which passed platinum rods 
to serve as electrodes; that on the positive side being alloyed 
with ten per cent of iridium. This V-tube was placed in a glass 
jar and surrounded with methyl] chloride. The liquid hydrogen 
fluoride was then transferred to it, the methyl! chloride boiling 
quietly at —23°, and the current of 20 Bunsen cells, having an 
ammeter in circuit, turned on. If a trace of water be present, 
ozone is at first evolved; and then as it disappears, the resistance 
of the liquid rises; so that the current ceases when it becomes 
anhydrous. A small quantity of hydrogen-potassium fluoride 
must therefore be added; and then the evolution of gas is con- 
tinuous and regular. At the positive electrode this gas is color- 
less, and silicium takes fire and burns brilliantly in it, as does 
adamantine boron, arsenic, antimony, sulphur and iodine. The 
metals also burn in it but less actively. Organic matters are 
violently attacked by it. A fragment of cork, near the delivery 
tube, took fire, and alcohol, ether, benzine, turpentine and petro- 
leum are at once inflamed on contact with it. The gas combines 
with hydrogen spontaneously in the cold and with detonation. 
Since direct experiment showed that neither ozone saturated with 
hydrogen fluoride, nor hydrogen fluoride itself, would produce 
