METHODS OF RESEARCH: APPARATUS 



83'. 



constructed microtome known as the Minot Rotary, which we 

 also have, and use occasionally. For some purposes, such as 

 making large sections with a long slant stroke, we have also 

 used the large Minot Precision Microtome, which is a very good 

 instrument but too cumbrous for our ordinary work. Another 

 excellent instrument which we use is the Spencer Rotary Micro- 

 tome No. 820. Our freezing microtome also is one made by the 

 Spencer Lens Co., of Buffalo, N. Y. 

 (Fig. 53). 



The style of razors recommended 

 for use with the Reinhold-Giltay 

 microtome are figured in "Bacteria 

 in Relation to Plant Diseases," Vol. 

 I, p. 123. 



Paraffin Oven. Any small 

 water-jacketed oven with a safe, self- 

 regulated, constant flame which can 

 be set very low will serve for keep- 

 ing at the proper temperature (59 

 to 60C.) the paraffin used in em- 

 bedding. For figure of a small 

 paraffin oven in use see "Bacteria 

 in Relation to Plant Diseases," Vol. 

 I, p. 118. This is sufficient for 

 private use, but where several per- 

 sons must be accommodated at 



the same time the large compartment oven devised by Professor 

 Frank R. Lillie is recommended. 



Section Straightener. For straightening out sections on the 

 slides we used formerly the low flame of an alcohol lamp under 

 an asbestos board, but more recently we have substituted an 

 electric constant temperature apparatus made by W. C. Heraeus, 

 G. m. b. H., Hanau a/M., Germany (Fig. 54). With a little 

 watching this warm-plate gives a temperature just sufficient 

 for straightening the sections without melting them. Previously 

 for the same purpose we tried a little electric oven made by The 

 Thermo-electric Instrument Co., Newark, N. J. (Freas' Electric 

 Incubator, Serial 111, voltage 220, wattage 15.0; 1" X 7" X 



FIG. 54. Electric warm plate 

 used for straightening out para- 

 ffin sections. Made by W. C. 

 Heraeus. G.m.b.H., Hanau 

 a/M., Germany. No. 450. G. 

 220 V. 



