2644 



Journal of Applied Microscopy 



excellent quality of alcohol, and is inexpensive. The apparatus is made of heavy 

 copper, tinned on the inside, and a block-tin worm. It is composed of a gas- 

 stove, an automatic water-bath, boiler, condenser, and receiver, (Figs. 1 and 5.) 

 The only especial requisite for the gas-stove is a stop-cock in the supply pipe 

 by which the gas flow may be regulated, thus permitting the stop-cock in the 

 gas main to be turned on full. A stove similar to No. 8157, Eimer & Amend's 

 Catalogue, 1902, p. 211, is satisfactory. 



Fig. I represents median plane through still. 



Fig. 2 shows relative position between tube H, D, and C. If the still is placed near or 

 against a wall, tube H should be a little in front of the plane through D so that the cock I may 

 be more easily reached. 



Fig. 3 shows course of block-tin worm from bottom of condenser to J in Fig. i, seen from 

 below upward. 



Fig. 4 is a side view of V, showing tube X. 



Naturally, the size of the still must depend on the amount of work to be 

 done. For making an amount of absolute alcohol used in our universities the 

 following dimensions are sufficient : a water-bath, eleven inches in diameter and 

 eleven and one-half inches high, with a substantial support one and one-half 

 inches above its bottom to support the boiler and still, will allow one and one- 

 half inches of water about the sides and bottom of a boiler eight inches in diam- 

 eter and ten inches high. The support for the boiler should be fastened to the 

 sides and bottom of the bath, with a small depression on the upper surface or 

 several small uprights to hold the boiler in one place. The automatic water 



