76 Intelligence and Miscellaneous Articles. 
year, we take as an example the following numbers in order to give 
an idea of the state of things : — 
Temperature, 
Centigrade. 
— 131-6 
Pressure at which oxygen 
began to liquefy. 
atmospheres. 
26-5 
-133-4 
24-8 
-135-8 
28-5 
We reserve the communication of the definitive numbers. 
Liquid oxygen, like liquid carbonic acid, is colourless and trans- 
parent. It is very movable, and forms a fine meniscus. 
Carbon disulphide congeals at about —116° C. Absolute alcohol 
at —129° C. becomes viscid like oil, and congeals to a solid mass 
at about — 130 o, 5 C. Of these also we reserve the communication 
of the definitive numbers. — Anzeiger der Tcaiserlichen Akademie der 
Wissenschaften in Wien, 1883, no. ix. pp. 74, 75. 
ON THE LIQUEFACTION OF NITROGEN AND CARBONIC OXIDE. 
BY PROFESSORS S. VON WROBLEWSKI AND K. OLSZEWSKI. 
Having succeeded in completely liquefying oxygen*, we tried in 
the same manner to bring nitrogen and carbonic oxide into the 
liquid state. The liquefaction of both these gases is considerably 
more difficult than that of oxygen, and takes place under conditions 
so similar that it is at present impossible for us to say which of the 
two gases liquefies more readily. 
At the temperature of about — 136° C, and under the pressure 
of about 150 atmospheres, neither nitrogen nor carbonic oxide 
liquefies : the glass tube containing the gas remains perfectly trans- 
parent, and not a trace of liquid can be perceived. If the gas is 
suddenly released from the pressure, in the nitrogen-tube is seen a 
violent effervescence of liquid, comparable only to the effervescence 
of the liquid carbonic acid in Natterer's tube when the latter is put 
into a glass containing hot water. "With the carbonic oxide the 
ebullition is not so strong. 
But if the expansion is not effected too suddenly and the pressure 
is not allowed to fall below 50 atmospheres, both nitrogen and car- 
bonic oxide are liquefied completely ; the liquid shows a distinct 
meniscus, and evaporates very briskly. Therefore neither of the 
two gases can be kept more than a few seconds as liquids in the 
static condition ; to retain them longer in that state a somewhat 
lower temperature would be necessary than the minimum which up 
to the present it has been possible for us to attain. 
Nitrogen and carbonic oxide in the liquid state are colourless and 
transparent. — Anzeiger der Jcaiserlichen Akademie der Wissenschaften 
in Wien, 1883, no. xi. pp. 91 , 92. 
* See preceding article. 
