July 12, 1912] 



SCIENCE 



HI 



International Commission on Nomenclature 

 was rendered in August, 1910, in favor of 

 restricting Astacus for the crayfishes and 

 Momarus for the lobsters, it is hoped that 

 this needless source of misunderstanding will 

 be eventually removed. 



Francis H. Hebrick 

 Western Eeserve Univeksitt 



a panum incubator with important modifi- 

 CATIONS 



One of the most pressing needs of a general 

 bacteriological laboratory is an incubator 

 which possesses compartments of different but 

 constant temperatures. Various types have 

 been constructed and are in use to-day. After 

 a rather extended investigation into the sub- 

 ject of incubators the writer chose the so- 

 called " Panum " model with certain modifi- 

 cations. An admirable description of this 

 incubator, together with certain improve- 

 ments which it has undergone in the Carls- 

 berg laboratory, is given in Klocker's " Fer- 

 mentation Organisms." ' A brief description 

 seems desirable here, in order to impress upon 

 those who are not familiar with the apparatus 

 its salient characteristics. 



The incubator consists of three main parts 

 (Fig. 1, A, B-C, and D) which are constructed 

 separately, preferably of thick sheet metal. 

 These three parts are soldered together. The 

 first compartment. A, is double-walled. The 

 space between the two walls is filled with 

 water, which is kept at the required tempera- 

 ture by a safety gas lamp which is controlled 

 by a thermo-regulator (&). The gas lamp is 

 placed under a projecting wing (a) of the 



" Published by Longmans, Green & Co., London 

 and New York. 



outer metal wall. As this wing may burn 

 through in the course of time it is connected 

 with the water jacket by means of screws and 

 flanges which are provided with rubber pack- 

 ing. The projecting wing may be replaced 

 when necessary, without any difficulty. The 

 space between the two walls of A is filled with 

 water poured in through holes in the top. 

 The water may be run off through a stopcock 

 situated on the wing. 



Compartment A is divided into halves by a 

 vertical partition. Division B-C is divided 

 into two compartments each of which is sub- 

 divided into three equal sections by vertical 

 metal partitions. All of the divisions are 

 provided with two shelves which may be 

 placed at any desired height. The last main 

 compartment, D, serves as a refrigerator. It 

 possesses an inner receptacle, the roof of which 

 slopes to the sides and back. This inner box 

 is cooled by water which trickles down over it 

 from ice which is held on a strong grating. 

 The water is run o£E through an opening in 

 the floor of the main compartment. The ice 

 container is covered with a metal lid over 

 which a thick wooden lid is made to fit closely. 

 The entire apparatus, with the exception of 

 the front, is covered by a layer of felt 8 centi- 

 meters thick and enclosed in a wooden box. 



In the words of the book, " Each of the 

 spaces 1 to 8 is provided with a tightly fitting 

 glass door, and doors of sheet iron are fitted 

 on each of the four large compartments, A, 

 B, C and D, which are closed tightly by press- 

 ing against rubber strips fitted on the parti- 

 tions. Four corresponding doors, also fitting 

 tightly, are attached to the wooden case, their 

 inner sides being coated with woolen pads. 

 All these doors are hinged below, and when 

 opened and resting in a horizontal position on 

 adjustable brackets may be used as tables." 



In the particular incubator under consid- 

 eration it seemed desirable to make a number 

 of changes or improvements over the model 

 just described. In the first place, heavy 

 copper sheeting was used throughout the 

 apparatus, with the view, of course, of 

 making all the parts more permanent. Be- 

 sides soldering the three separate divisions 



