NOVBMBEE 13, 1908] 



SCIENCE 



667 



PLUMBING 



It is well recognized now that the plumb- 

 ing in a laboratory should be exposed. 

 This is accomplished in some cases by hav- 

 ing a pipe trough in the floor, covered by 

 a removable trap or grating. This is un- 

 satisfactory, as such a conduit constitutes 

 an open sewer in the floor. 



The piping can be best suspended from 

 the ceiling. This need not be in a hap- 

 hazard manner, presenting an unsightly 

 appearance, but the pipes may be carried 

 in such order as to really constitute a 

 decorative feature of the rooms. In carry- 

 ing piping from floor to floor, they may be 

 placed in a cupboard in the wall. The face 

 of the cupboards, being held in place by 

 screws, will give ready access in case there 

 be need to inspect or make repairs. 



It is advisable to insert a valve in the 

 main which leads to each laboratory. By 

 this means, in case there is need for re- 

 pair in any one particular laboratory, only 

 that laboratory is thrown out of commis- 

 sion for the time. 



As the result of very careful study of 

 the matter of the composition of the waste- 

 pipe, I will say that I regard a high carbon 

 cast iron as being the most satisfactory. 

 This should be dipped in heavy tar which 

 has been heated until it is perfectly fluid. 

 These drains, with a suitable dip and trap, 

 lead to vertical chemical wastes. The 

 latter may well be of glazed earthenware 

 joined with hot tar and surrounded by six 

 inches of concrete. By having several 

 trunk lines, vertical and opening out 

 through the roof, there is little danger of 

 clogging, and corrosion is reduced to a 

 minimum. Obstructions may be removed 

 by dropping a weight, suspended by a 

 cord, through the opening above the roof. 



The form of sink connecting with these 

 wastes is not a mere matter of taste. 

 Alberene serves the purpose admirably, but 



where it is possible, I think the porcelain 

 overflow roll-rim flush sinks should be 

 used. A perforated outlet prevents large 

 solids being washed into the system. A 

 rubber disk, or even a piece of paper, 

 placed over the perforations gives a pneu- 

 matic trough of constant level. Should 

 concentrated acid or alkali by chance come 

 into the sink, it may be instantly diluted 

 by turning a valve. 



Undoubtedly whitewashed brick walls 

 constitute a very satisfactory finish for a 

 laboratory. White plaster is more attract- 

 ive, and still more satisfactory is the white 

 plaster which has been given three coats of 

 acid sulphur-proof paint. A combination 

 lithophone and zinc oxide has proved emi- 

 nently satisfactory. Incidentally it may 

 be stated that a number of paints were 

 tested and found wanting. 



All metal ware, which is likely to be ex- 

 posed to any fumes whatever in the labora- 

 tory, should be painted with an acid-proof 

 paint, and that which is underneath the 

 hoods or between the desks may be treated 

 with a black damp-resisting paint. All 

 pipes upon the ceiling, etc., may be covered 

 with the white enamel acid sulphur-proof 

 paint referred to above. 



VENTILATION 



There are various systems for ventilating 

 buildings in vogue. The one settled upon 

 by our ventilation expert is known as the 

 push and pull system. The air is filtered, 

 drawn over tempering coils by a large 

 motor-driven fan, carried by ducts, and 

 driven in at the upper portion of the room. 

 A fan in the attic pulls the air from the 

 bottom of the rooms through corresponding 

 ducts. Some prefer the pressure system, 

 arguing that the tendency of the air to leak 

 in around the windows is avoided, and, 



