Potash bulb

Kali-kugel, /. potash bulb, -lauge, /. potash lye, caustic potash solution, -losung, /. potash solution, -metall, n. (metallic) potassium. -olivenolseife, /. potash olive oil soap, -praparat, n. potash (or potassium) preparation. -reibe,/. (Petro. ) potash series, -roh-salz, n. crude potassium salt, -salpeter, m. 

Preparation.—Carbon disulphide is prepared by passing sulphur vapour over red hot charcoal. The preparation may be carried out on a small scale by heating pieces of charcoal in a combustion tube placed in a furnace slightly tilted, a Liebig potash bulb, immersed in ice, being attached to the lower end of the tube, and small pieces of sulphur introduced into the upper end of the tube which is then closed with a cork. Sulphur vapour passes over the red-hot charcoal and impure carbon disulphide containing sulphur in solution is gradually formed and collects in the cooled receiver. 

The difference in the weights of the potash bulb and the silica gel before and after the absorption gives the amount of phosgene in the sample. 

Copper oxide was used instead of potassium chlorate for combustion analyses by Gay-Lussac, Dobereiner, and Prout, who later used copper oxide and oxygen gas passed through the tube. Ure" and G. Bischof also used copper oxide, but the simple combustion apparatus with potash bulbs (Fig. 20) invented by Liebig was a great advance on previous methods. 

The substance mixed with dried copper oxide was burnt in the hard-glass tube A, heated with burning charcoal in the sheet-iron pan. Water was collected in the calcium chloride tube B and carbon dioxide in the potash bulbs D, protected from loss of moisture by another calcium chloride tube E weighed with D. After the combustion the drawn-out tip of A was broken off and a slow stream of air aspirated through the apparatus. 

Mitscherlich used a horizontal tube heated by a Hess s spirit lamp and special potash bulbs copper oxide was used for the combustion and the reduced copper was re-oxidised by a current of oxygen from potassium... 

Instead of red phosphorus and water the potash bulbs contain a solution consisting of arsenious anhydride... 

The determination of ethoxyl is carried out exactly in the manner described in the preceding section for methoxyl except that the water in the condenser and in the bath surrounding the potash bulbs should be... 

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