4 8 PLANT PHYSIOLOGY 



SINK. An indispensable part of the furnishings. It should stand prefer- 

 ably in a room apart from laboratory and greenhouse, though this is not essen- 

 tial as in the case of the gas-table. It should be porcelain -lined, eighteen 

 inches wide, five feet long, and two and a half feet from the floor. It should 

 be provided with several taps for (a) ordinary water-supply, to which a hose 

 can be attached for wetting down the greenhouse (page 39), (6) a small noz- 

 zle to which small rubber tubing can be attached, (c) a Chapman exhaust, 

 permanently attached, (d) a small water-motor with emery-wheel, very use- 

 ful for sharpening instruments, grinding glass, etc., (e) a water-blast for 

 aerating cultures and the like. Beneath the sink should hang, ready for use, 

 two or three granite iron pans for washing, and a pneumatic trough; and 

 over it should stand, in proper racks, three or four different sizes of cylin- 

 drical graduates, and a series of different sizes of funnels. Here also 

 should be placed glass shelves for the chemicals most in use. 



TOOL -TABLE. This may well stand in a corner of the laboratory before 

 a window. It is used for simple carpentry and metal -work ing, and, in gen- 

 eral, for the construction or adaptation of apparatus. It should have a solid 

 wooden top, two inches thick, two feet wide, six feet long, and three feet from 

 the floor, and should have ample drawers below for the reception of tools 

 and the proper supplies. On it should be a vise, and over it should hang 

 spools of copper wire. 



STEAM STERILIZER, for sterilizing pots, saucers, moss, and other germi- 

 nation appliances, and for other similar uses. A very good form is the 

 Arnold (sold at moderate cost by supply companies), of which the largest 

 size is the most useful. It should stand always ready for use on the gas- 

 table. For articles or materials often needed in sterilized condition, it is 

 time-saving to provide a large glass jar with ground cover, into which they 

 are introduced sterilized and hot, and from which they may be withdrawn 

 as needed. 



STILL, for providing the essential distilled water. One of the several 

 automatic forms is best, and it should be permanently attached to the wall 

 over the gas-table, with suitable water connections. Of course where steam- 

 heat is used, it is more economical to condense the distilled water from the 

 steam -pipes by carrying the steam through a pipe cooled by water from a tap. 

 For some special purposes, stills which yield traces of metals will not answer, 

 and, to provide for this, some one of the glass forms now offered by supply 

 companies should be on hand ready for use. 



AIR-PUMP. For practically all purposes the most convenient is a Chap- 

 man exhaust, which, attached to a water-tap yielding a good pressure, will 

 give rapidly within one per cent of a vacuum. It should be connected with 

 a gauge, preferably a mercury manometer affixed to the wall, which has the 

 advantage that it renders the exhaust directly visible. 



ASPIRATOR AND AERATOR, necessary for drawing air in some phases of 

 gas analysis. For this the Chapman air-pump can be used in some cases, 

 but where gentler and steadier action is necessary, one of the standard aspira- 

 tors, sold by all supply companies, should be used. Or, a very good form 

 may be adapted from two large bottles on the principle illustrated by the 



