e^r 



692 



693 



694 



W Dr. Paine's Laboratory Filter, mounted complete with filter candle as shown 



A. B. 



Candle, 5| by |,\ in. Candle, 6 by i in. 



3/6 7/6 each. 



Description. The apparatus consists of a cylindrical glass tube (a) having a small side exhaust tube (B). 

 IK h is partly covered with a piece of rubber tubing (r 1 ). Over the latter is slipped a larger tube (f) furnished 

 th a nozzle and plugged with cotton wool. 



The cylindrical tube is corked by a rubber stopper through which passes a porcelain " candle " or " bougie ' 

 In. which reaches to the bottom of the tube. 



The candle is also corked by a rubber stopper through whicli pass two glass tubes (D) and (E). 

 The tube (D) (delivery tube) extends a short distance into the candle, whilst its horizontal portion is pro- 

 cted by a larger glass tube (the cap) (F), closed at one end and connected to the smaller tube by a piece of 

 ibber tuLing (r 11 ) similar to (r 1 ). 



The tube (E) (the exhaust tube), is fitted with a larger tube bearing a nozzle (o) by a piece of rubber tubing 

 '") similar to tube (F). 



Manipulation. The candle and its attachment are sterilised separately. The fluid to be filtered is put in 



r cylindrical glass tube (A), and after all the rubber connections have been made air-tight, the exhaust tube 



|) connected with an exhaust pump. The fluid is thereby sucked into the candle, and when sufficient In- 



i--rd through, the apparatus is disconnected with the pump, the cap (r)is slipped off the rubber tubing (r") 



ltd the fluid poured out through the delivery tube into a sterile receptacle. 



N.B. Care should be taken to disconnect the pump before any fluid has been drawn on into the cotton 

 il of the exhaust tube ; otherwise the fluid will not flow readily out of the delivery tube. 



The apparatus may be used for combined cultivation and filtration. For this purpose the cylindrical tulic 

 may be plugged with cotton wool and served as a receptacle for the culture medium, which is subsequently 

 it-red by attaching the candle. In this way the risks attending pouring dangerous cultures from one vessel 

 I another may be avoided. 



For anaerobic cultivation it is only necessary to join two cylindrical tubes together as shown in Fig. 2 by 

 piece of pressure tubing fitted with a screw clip, the two tubes being corked by rubber stoppers. 



In one tube is placed the culture medium, in the other absorbent fluid, e.g. a solution of caustic potash 

 Hid pyregallic acid in the tabloid form. 



When all the oxygen is absorbed, the culture tube is sealed off by the screw clip and detached from the 

 Ikhatist tube containing the absorbent mixture. 



|93 Novy's Filtering Apparatus, complete with stand . . . . each 



94 Novy's Filtering Apparatus, new form, for filtering bacterial fluids, the cylinder is fitted 

 with ordinary candle ...... . . each 



See Centralblatt jiir Bacteriologie, Band XXXV., No. i, 5th November, 1903). 



95' Klein's Filter, small size, for filtering toxins in vacuo, with Pasteur-Chamberland porous 



candle, 6 by i in. reservoir to hold 100 cubic centimetres . . . . . . eat -h 



695 



18 

 100 



150 



CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 



141 



