68 CULTURES OF BACTERIA. 
Fic. 43.—Brown University electric water or paraffin 
bath.! 
1A porcelain-lined dish fitted with a tin cover, provided 
with four doors. In the figure the cover is raised from the 
dish to show the thirty candle-power electric lamp which 
projects through the cover into the water or paraffin below. 
The lamp is provided with a regulating socket giving 
