1A), the peripheral gap between the chamber being filled with an insulating material (12) the wall of the outer

chamber (1) being provided with a hole for inserting a thermometer (10) for measuring the temperature, the three

sides of the inner chamber (1A) being lined with heating element (2) the two ends of the heating elements being

connected to conventional electric source, the temperature of the chamber being controlled by means of a gas filled

thermostat (3 &4) the inner chamber having a perforated horizontal partition (18) for housing the sample to be

analyzed, the front portion of the incubator being provided with a door, also lined with the said insulating material

(12) a pilot indicator lamp (17) being fixed on the outside chamber in series with the above said thermostat for

indicating the on/off position of the thermostat another indicator lamp (16) being also fixed on the front side of the

outer chamber indicating the presence or absence of electric supply to the incubator.