On the Liquefaction of Gases. 189 



over in silence is all the more astonishing, because as soon as 

 the above-mentioned Bulletin was printed I sent a proof of it 

 to Prof. Dewar ; I also forwarded him proofs of my other 

 researches, knowing that they interest him. 



The apparatus I constructed and described works very well 

 and can be used without danger, so that in October of the 

 same year (1890) I was enabled to obtain 100 cub. centim. of 

 liquid oxygen in the presence of an audience consisting of 

 over 100 students. In the following year, during the Congress 

 of Polish naturalists and physicians in Cracow (July 1891) I 

 obtained 200 cub. centim. of liquid oxygen in the presence of 

 a good many physicists, and showed its peculiar properties ; 

 as, e. #., its bluish colour and its absorption spectrum. Subse- 

 quently, without having altered my apparatus in any way, I 

 got about 200 cub. centim. of liquid air and used it as a 

 frigorific agent in order to liquefy hydrogen. The construc- 

 tion of my apparatus is very simple, and it can easily be 

 enlarged by using a steel cylinder of the capacity of 300, 400, 

 500, or more cubic centimetres. The only reason that I have 

 never hitherto employed a steel cylinder of greater capacity 

 than 200 cub. centim., is the circumstance that the quantity 

 of oxygen or air which can be liquefied in this cylinder was 

 quite sufficient for my experiments. 



After these remarks, I shall now give a summary of the 

 more important results of my former labours concerning the 

 liquefaction and solidification of gases, and then describe 

 the apparatus I constructed, which serves to obtain great 

 quantities of liquefied oxygen and air ; also stating my experi- 

 ments made in order to liquefy hydrogen, by using large 

 quantities of liquid oxygen or liquid air as frigorific agents. 



Summary of the Results of my former Experiments. 



In 1883, and for several years following, I liquefied the 

 gases in a strong glass tube, about 30 centim. in length, 14-18 

 millim. in diameter within, with walls from 3 to 4 millim. 

 thick. Oxygen, nitrogen, atmospheric air, carbon monoxide, 

 nitric oxide, and methane, submitted to the influence of cold 

 in the tube by means of liquid ethylene, boiling in vacuo at a 

 temperature of — 150° C, were easily liquefied under a pres- 

 sure not beyond 50 atm. As my experiments proceeded, I 

 published their results in the periodicals I have mentioned ; 

 and a detailed description of the apparatus I used in my 

 experiments is contained in Wiedemann's Annalen der Physik 

 und Chemie, 1887, vol. xxxi. p. 58, under the title " K. Ols- 

 zewski. Ueber die Dichte des fliissigen Methans sowie des 



