EXPEKIMENT HTATION REFORTIS. 12.'3 



cordingly, we determined to introduce this feature with some modifica- 

 tions in construction of the new staclv. The illustrations which are 

 given contain the details necessary to an understanding. In order to 

 secure the greatest possible advantage in the use of gas pipes, collars 

 have been laid in the walls of the stack, leading from the interior to the 

 exterior. These collars are five in number and consist of two-inch 

 pipe. One and one-fourth inch pipe is used for grating. One end of 

 the pipe used as grating is inserted about an inch into the two-inch 

 pipe collar. The other end rests on a ledge, but remains one or two 

 inches away from the wall. When a fire is built below, the pipes 

 become heated, and cold air is taken from outside, passed through, 

 and out through the flue of the chimney. This has a tendency to keep 

 the pipes cool. Another advantage the pipe has, lies in the failure 

 of the furnace fire to heat the top and bottom of the pipe sufficiently 

 to cause bending. A year ago we placed five one and one-fourth-inch 

 pipes in this stack for the purpose of supporting the material. Today, 

 only one is slightly bent. During the year we have burned a great 

 number of hogs, have burned the bedding used in the stable, have put 

 in this furnace all of the refuse from the laboratorv, and it has been 

 used to some extent by other departments on the campus. We feel very 

 well satisfied with the results. A one and one-fourth inch pipe is more 

 easily secured than grates, and costs very much less. If our experience 

 continues in the future as in the past, we shall not have many pipes 

 to provide. 



Because of tlie success of this scheme, I make bold to offer plans 

 for construction to those who have wrestled with this same problem, 

 but have not vet satisfied themselves. 



TO PREVENT THE DRYING OF MEDIA. 



OTTO RAHN. 



We keep tubes of media in large glass jars with covers, containing 

 70-150 test tubes. The bottom of the jar is covered with excelsior 

 (which is more elastic than cotton), and is kept moist by a half per 

 cent mercury bichloride solution, which stands about 1 cm high in 

 the jar. 



