114 SUMMARY OF CURRENT RESEARCHES RELATING TO 



fared them to a mixture of ether and paraffin (ether 5 c.cm., paraffin 

 m.p. 50° C. = 4 grm.) for 3 or 4 hours, and then for a similar -period to a 

 second solution (ether 5 c.cm., paraffin m.p. 50° C. = 4 grm.), The ether 

 and paraffin solution is easily made by placing fragments of paraffin 

 together with the ether in a well stoppered bottle and incubating at 

 from 30-40° C. ; care must be taken not to bring the bottle near an open 

 flame. After the second impregnation in the ether-paraffin mixture, the 

 pieces may be transferred to pure paraffin m.p. 50° C. 



As ether readily dissolves celloidin, the author saw his way to perfect 

 a method for a mixed imbedding. In this method the pieces are re- 

 moved from absolute alcohol to ether for 12 to 24 hours, and then to a 

 3-4 p.c. solution of celloidin in ether. This is followed by the ether- 

 paraffin solutions, and finally by pure paraffin. From blocks made by 

 this latter method sections may be obtained which are not only very 

 thin, but form ribands quite easily. Such sections may be stuck on the 

 slide by the water, albumen or Schallibaum's methods. While section- 

 ing, the block does not require moistening with alcohol, though when 

 the cutting is finished, it is advisable to cover the surface with paraffin. 



(4) Staining- and Injecting 1 . 



Picric-acid Carmin.* — R. Thoma finds that picric-acid-carmin is of 

 great use for double staining, for staining nuclei and for decalcified 

 osseous tissue. 1 grm. of picric acid is dissolved in 100 c.cm. warm 

 distilled water, and filtered. To the hot filtrate is added ■ 5 grm. red 

 carmin. The mixture is warmed until the powder is dissolved, is 

 constantly stirred and brought to the boil once. It is allowed to cool 

 slowly, and after about 24 hours is filtered. 



Picric-acid-carmin stains sections in about 20 minutes. The sections 

 are washed in tap-water and differentiated with 1 p.c. picric acid 

 solution. After several washings in water the sections maybe examined 

 in glycerin or dehydrated and mounted in balsam. 



New Method of Staining Micro-organisms.t — F. Loeffler describes 

 the following methods for staining micro-organisms, especially spiro- 

 chastae, gonococci and diphtheria bacilli. The film is fixed with ethyl- 

 alcohol, and then treated with 3 drops of ' 5 p.c. solution of sodium 

 arsenate and 1 drop of 0*5 p.c. solution of malachite-green-zinc- 

 chloride (Hochst). This is warmed for one minute and then the 

 preparation is carefully washed. 5-10 drops of Giemsa stain are mixed 

 with 5 c.cm. of J p.c. glycerin, and brought to the boil. The film is 

 then treated for 4-5 minutes with the hot solution, and afterwards 

 washed with a stream of water. 



Another procedure given consists in mixing 4 parts borax (2 • 5 p.c), 

 methylen-blue (1 p.c), with 1 part polychrome methylen-blue, and then 

 adding an equal quantity of • 05 p.c. brom-eosin B extra or extra A. G. 

 (Hochst). The preparations are treated with the warmed solution for 

 one minute, and then immersed in a solution consisting of saturated 



* Zeitschr. wiss. Mikrosk., xxiv. (1907) p. 139. 



t Deutsche Med. Wochenschr., 1907, No. 5. See also Centralbl. Bakt., 

 lte Abt. Ref., xl. (1907) pp. 307-8. 



