( 67() ) 



III I lic same way the i-cgeiierator and retViueralor for mellivl- 

 chloride arc coiiibincd (see Qü J'l. Jj ior Hie elcxatioii and I'l. 1 for 

 tlie sec'tion) in one apparatus whieli we will eali (he iiiethylchloride 

 boiling- vessel. The experience with the ethylene hoiling vessel has 

 been put to use, so that in ils tuni also the niethylchloride apparatus 

 will serve as a model for an ini[>rove(l ethylene lioiling \essel. The 

 increase of the ratio iietween the surfaces of regenerator and refri- 

 gerator allows the melhylchloride to leave the ai)paratus at nearly 

 ordinary temi)erature, even when the l)rRCKHARDT pump asdescril)ed 

 Comm. N" 8.3 Apr. '03 sucks with its full force, which coidd not 

 be obtained before with the ethylene l)oilijig vessel. The condensing 

 surface measured in the tube is about 0.9 M-., and the regenerator 

 surface, similarly measured, nearly the same. 



The walls of the boiling vessel are soldei-ed to form one whole ; 

 those of the refrigerator 6'c/,„ and Da (see PI. 1) are of copper 1 nnn. 

 thick, that of the refrigerator Fa of thin brass 0.5 mm. thick. The 

 neck A' of the refrigerator is soldered to the regenerator and this 

 again to the mouthpiece Ga. Owing to the length of the regenerator 

 and the thinness of the walls it is possible to make the latter of brass. 

 Even w ith this material the heat conductioji is of no importance. 

 Since I he vessel nnist l)e e\acuated it nmst show a considerable 

 resistance to external pressure. The resistance of the Avails themselves 

 is in the first place increased by the addition of small ridges Avhich 

 are shown as Ca^^ in the main drawing with the detail of the Avail 

 to the right and the section to the left. In the conical space D six 

 triangular copper plates Do^^ (cf. principal figure and the section at 

 bottom right of Pi. 1} give the necessary stiffness. These ha\e flanges 

 -Z)iji, i>6j„, which rest on one side oji the bottom, on the other 

 side they carry the conical Avail of the vessel through three rings 

 yjtj , J)c., and Dr^ . Resistance to outAA^ard pressure, Avhich becomes 

 necessary Avhen leaks have to be sought, is proA'ided by pressing the 

 l»ottom of the i-efrigerator against the plates JJij^o by means of four 

 Avooden balks Cd, Avhich also protect Ca^, pressing on crossed laths 

 Co ^vhich are screAved up to rest on the round upper surface by 

 means of steel rods Cc^ and a ring Ccg • 



In contrast Avith the scheme of the ethylene boiling vessel, it was 

 not considered necessary that the height of the liquid should remain 

 very little above the Avindings of the condensation spiral. To condense 

 oxygen in the ethylene boiling vessel it Avas of all importance that 

 the temperature of the condensation spiral should fall as far as pos- 

 sible and thus that the ethylene should boil under a very Ioav pressure. 

 2sow in that case there woidd be no advantage in the vacuum pump 



