BAIRD &TATLOCK. (LONDON) LTD. 



4047 

 047 s FriswelPs Improved Apparatus, for Sulphuretted Hydrogen, CO 2 Hydrogen, etc. 



Diameter of centre bulb 

 Price 



4 



15/- 



5 



21/- 



6 in. 

 25/- each. 



(Chemical News, 23rd September, 1904.) 



FRISWELL'S IMPROVED KIPP'S APPARATUS. 



ADVANTAGES. 



The following serious defects observed in working the ordinary Kipp's apparatus are reduced to a minimum, 

 id, in fact, practically abolished in Friswell's apparatus. 



1. Rapid degeneration of the acid liquids and early appearance of sluggishness in reaction. 



2. Wastefulness of acids. 



3. Necessity for frequent recharging. 



DESCRIPTION. 



The form of the apparatus shown in the above illustration may be briefly described as consisting of the 

 sual three bulbs. In bulb I a ground-in tube passes down to the bottom of the lowest bulb. B is a stopcock 

 >r drawing off the contents of i. c is the usual outlet for the gas in bulb 2. 



METHOD OF USING. 



Before use the tube A must be securely fastened into its seating in bulb i. To do this, gently warm the 

 round part of the tube and of the bulb, then smear on the ground part of the tube a very small quantity of good 

 esh marine glue. Press the tube firmly home with a turning movement. None of the glue must get on to the 

 jter ground neck of bulb i. Charge the centre bulb 2 with the marble, zinc, or ferrous sulphide, and pour down 

 IB centre tube by means of a funnel sufficient strong calcium chloride, zinc sulphate, or ferrous chloride solution 

 > fill the lower bulb nearly to the top. Now pour in the acid until the uppermost bulb is so filled that the acid 

 :ands an inch or so above the flared lip of the standing tube A. Open the gas cock slightly so as to allow the 

 ;:id to descend very slowly through the centre tube. When it reaches the bottom of the apparatus, it rises 

 irough the strong salt solution and reaches the centre bulb at nearly full strength, and when the gas pressure 

 I ses, the exhausted liquor will be slowly pressed back to the upper reservoir, and is particularly noticeable when 

 ic gas cock is closed. 



The liquids having changed places, the strong salt solution forced back to replace the acid will be seen falling 

 ver the lip of the flared tube in the upper reservoir through the stronger acid therein. When an accumulation 

 f this denser liquid in the upper reservoir takes place to such an extent that its level approaches the upper part 

 f the standing tube, it is drawn off by the cock B and fresh acid carefully poured into tube A by means of a funnel. 



761 



