CHEMICAL LABORATORY AT THE UNIVERSITY OF SYDNEY. 179 



A toe-space is left in front of the bench instead of giving it an 

 overhanging top. The gas used for lighting the benches is made 

 use of for ventilation also, the heated products of combustion 

 passing into the ventilating flues from the bench draught cup- 

 boards. When not liglited there is a valve which can be closed 

 to prevent the draught in the cupboards being spoilt ; an 

 advantage of the upcast draught is that the heat from operations 

 carried on in the draught cupboard assists the draught, which 

 is not the case when the draught is a down one. All the 

 gas and simple water taps are made with lever handles, since they 

 are more I'eadily turned, and serve as guides to show how far the 

 supply is turned on. 



In the main laboratory every bench is provided with the 

 following fixtures : — Two cupboards for each student, two 

 drawers, subdivided, and with a tray ; one draught cupboard for 

 each pair of students, one basin for each pair of students, one 

 sulphuretted hydrogen tap for each pair of students, an aspirator, 

 water, and distillation water tap for each, adjustable book rest 

 adjustable desk slope for note book, bicycle seat or rest, matchbox 

 holder, ink well, name plate, shelves for re-agents, cast iron 

 heating plate, three retort rings, three filtering rings to fit into 

 slots in uprights of the draught cupboards (Plate XVII.), or to 

 run on iron rods fitting into the bench top. 



The draught in the flues is maintained by gas jets, impinging 

 upon tire-clay domes. 



It is intended to line the sheet-iron flues with asbestos boai'd, 

 well saturated with tar or other impervious substance, to preserve 

 the iron from acid fumes as much as possible. The top of the 

 benches are to be of teak, if possible, and grooved underneath 

 like drawing boards to prevent warping from the damp of spilt 

 licjuids and the heat of the lamps ; they are also to be saturated 

 with paraffin wax. 



A low rose burner (Fletcher's) with stand for sand plate, iron 

 plate and asbestos, or evaporating basin, is placed for each student 

 in the draught closets, so that he is not so much tempted to 

 evaporate acid liquids outside, and thus till the room with fumes. 

 The gas jets in the draught closets for ventilation are to be made 

 of steatite or tire clay, to prevent corrosion from acid fumes. 



A cover is provided for the sink in the centre, in case a student 

 should want a broad and open space to work upon. The receivers 

 below the basins are of earthenware, since lead is apt to corrode 

 very quickly. The overflow of these is arranged to be at least 

 three inches from the top, otherwise any sudden flow of water into 

 the basin causes an overflow in the basins below, and a consequent 

 flooding of the floor (Plate VII.). If leaden basins should have 

 to be used, they will be dished to prevent acid liquids remaining 

 and causing corrosion. For the same reason it is intended to 

 give all leaden gutters and drain pipes a good fall. If an open 



