1088 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



Supports for slides ia rectangular 

 basins. 



of tlie basin. For each basin there is also a copper lid with a button 

 handle in the centre and a hole, 1/2 in. in diameter, near this for a 

 thermometer. When the bath is once regulated this thermometer can 

 of course be dispensed with and the hole in the lid can be plugged 

 up with a cork. By this arrangement the paraffin dishes are always 

 kept dry and at a uniform temperature all over. The four rectangular 

 basins are used for warming the slides. In each of them is a movable 



rack made of two tin slips, each about 

 1/2 in. wide, and folded as shown in 

 fig. 254. Each of these basins also 

 has a copper lid with a button handle 

 in the middle. 



Near the centre of the bath a tube 

 1 in. in diameter passes from the top 

 down to and through the bottom. 

 This tube is the jDassage way for the 

 glass tube that connects the burner under the bath with the gas- 

 jet above the centre of the bath, and it should be soldered to the 

 upper side as well as to the under side of the bottom of the bath. 

 Near this tube are two others, each 1 in. in diameter, that project 

 about 1^ in. above the upper surface of the bath, but are soldered 

 with their lower ends flush with the under side of the top of the bath. 

 One of these tubes is for the automatic regulator, and the other is for 

 the thermometer. Through them the water is put in or taken out 

 of the bath. The thermometer and regulator are each in a test-tube 

 with holes blown in the sides, about IJ in. from the bottom, and with 

 a good flange on the upper edge by which it is supported on the 

 copper tube. A bit of cotton in the bottom of the test-tube protects 

 the mercury bulb of the regulator or thermometer from any jars 

 against the hard test-tube. The holes in the sides of the test-tube 

 allow the water of the bath to come in direct contact with the 

 mercury bulbs and at the same time they are up high enough to keep 

 the mercmy from running into the bath should either of the mercury 

 bulbs break while in the tube. The copper bath is supported in a 

 square box-table, the top of the bath being flush with that of the table. 

 This table is essentially a box on four legs, with a hole in the 

 top slightly more than 28 in. in diameter, and with a door at one 

 end. The bath is supported on four props that rest on the lower 

 shelf of the table, and around the inside of the table is a lining of 

 common tin to protect against possible accident. By this means a 

 steady flame is obtained and the loss of heat is reduced to a minimum ; 

 and by grouping the regulator, thermometer and gas-pipe near the 

 centre of the bath, hindrances are practically done away with. There 

 is also connected with the gas-jet a small home-made glass Bunsen 

 burner that is attached to the glass gas-tube a little above the bath. 

 It is very convenient for warming dip-tubes, lifters, &c. In so large 

 a bath as this two flames are required, but both are burned very low. 

 The one burner is connected directly with the gas-jet and the other 

 by way of the regulator. After the bath has, so to speak, been once 

 set it runs on uniformly and requires no attention. It is regulated 



