ZOOLOGY AND BOTANY, MICROSCOPY, ETC. Ill 



to the microtome. The side pipes are connected by tubes s 1 s 2 ; s x joins 

 on to a funnel and is supplied with a stop-cock T ; s 2 connects with a 

 suction apparatus \) (water pump) which exhausts the air in the chamber. 

 The apparatus is worked by pouring in ether through the funnel, 

 and then (having closed T) opening P. In about half-a-minUte the speci- 

 men which lies on the surface K is frozen, and will keep so for about 

 15 minutes. The apparatus works well, the consumption of ether is 

 small, and though intended for the Schanze can be adapted to any 

 microtome. The measurements of the freezing box are : lower surface 

 4-2-5 cm. ; upper surface 2*5-2 cm. ; height 3 cm. 



Electrothermal Paraffin Bath. * — Dr. E. H. Steen has devised an 

 apparatus in which the electric current from the main is utilised to raise 

 the temperature of a paraffin bath by means of the heat radiated from 

 one or two ordinary lamps placed in an asbestos box beneath it. A 

 mercurial thermostat placed in the bath maintains the temperature at a 

 constant level by causing the lamps to be switched off and on when the 

 temperature tends to rise or Ml below the degree required. An incubator 

 could be worked by the same apparatus, as the upper wire in the thermo- 

 stat can be adjusted for any required temperature. The bath works 

 satisfactorily without any attention, and its temperature does not alter 

 to an extent which is appreciable to any ordinary thermometer. 



Paraffin Bath heated by Electricity.! — CI. Eegaud and E. Fouilliand 

 have devised a paraffin bath which is heated by an electric current. 

 The inventors claim that it possesses many advantages over baths 

 heated by gas or petroleum, that it is much lighter, and can be manipu- 

 lated with greater facility. For saturating the pieces, wire baskets, 

 suspended by a wire in the paraffin bath, are used. 



Carbon Bisulphide in Paraffin Imbedding-.l — Prof. M. Heidenhain 

 describes a new method of imbedding in paraffin, carbon bisulphide 

 being used for saturating the objects. Three glass vessels with ground 

 stoppers are required. One contains a mixture of equal parts of bisul- 

 phide and alcohol, the other two pure bisulphide. The dehydrated 

 pieces are passed through these three bottles, remaining 24 hours in 

 each. For imbedding, two thermostats are used, one at from 36° to 38°, 

 the other from 56° to 57°. Two other similar glass-stoppered bottles 

 are placed one on eacli of the two thermostats. Each bottle contains bi- 

 sulphide (about \ to -j- in. in height), and in each is placed as much paraffin 

 as will dissolve. "When the pieces have been passed through both mix- 

 tures, from the lower to the higher, they are removed to pure paraffin at 

 55°, and the last step repeated. In the two pure paraffin baths the pieces 

 remain for an hour to an hour and a half. The repetition is necessary 

 in order to completely remove the bisulphide. The results from the new 

 procedure are excellent, but certain precautions are necessary. On 

 account of the inflammability of the bisulphide the manipulation should 

 be carried out in a part of the laboratory remote from open fire or flame. 

 The disagreeable odour may be avoided to a great extent by refraining 



* Brit. Med. Journ., 1901, ii. pp. 1733-4 (1 fig.). 



t Journ. Anat. Physiol., xxxvi. (1900) pp. 574-9 (3 fi^s.). 



X Zoitschr. f. wiss. Mikr., xviii. (1901) pp. 166-70. 



