1094 SUMMARY OF CURRENT RESEARCHES RELATING TO 



The process is improved by means of any apparatus which will supply 

 a continuous current of fluid. It is scarcely necessary to state that 

 other fluids than water may be used for this contrivance. 



Histological Technique.* — In " Notes " under this heading, Mr. 

 C. S. Minot makes some very useful and interesting observations, the 

 most important of which refers to the clearing up of celloidin 

 sections. 



A mixture of 3 parts of white oil of thyme and 1 part of oil of 

 cloves " clarifies sections very readily and softens the celloidin just 

 enough to prevent the puckering which is so annoying with thymo 

 alone." The author thinks that this process, which is the discovery 

 of Dr. E. K. Dunham, may be improved if tho proportions bo 

 4 to 1. 



For hardening purposes the author found the use of warmth with 

 Midler's fluid to be inferior to the use of cold. Nitric acid in cases 

 where the specimen is of small size, and especially when it has 

 begun to deteriorate, is said to be very valuable. One part com- 

 mercial nitric acid (strong) diluted with 9 parts of water, forms tho 

 solution in which the specimen is placed for 3 to 5 minutes. It is 

 then transferred to running water for 15 to 20 minutes ; 30 per cent, 

 alcohol for 10 minutes ; 50 per cent, for 1 hour, and kept in 70 per 

 cent, which is changed daily until it no longer takes on a brownish 

 discoloration due to the acid. 



In staining, after giving a formula for a neutral carmine solution, 

 and for an alcoholic eosin solution, with a note on Weigert's hemato- 

 xylin, the author recommends a pier ocar mine made by boiling 1 grm. 

 powdered carmine, with 200 c.cm. of water plus an excess of picric acid 

 for half an hour ; allow to stand and cool ; decant the clear fluid, add 

 fresh water, and if necessary picric acid, boil, cool and decant, repeat 

 this operation until all the carmine is dissolved. Place the decanted 

 fluid in an evaporating dish, add about 1 grm. thyme oil and stand in 

 a warm place until the volume is reduced to 25 c.cm., let the solution 

 cool, filter, wash out the residue which should be on the filter with 

 25 c.cm. water, dilute the filtrate with 50 c.cm. water. The solution 

 keeps indefinitely, and gives a stronger differential colouring of the 

 tissues than Eanvier's picrocarmine, but the contrast between the 

 nucleus and the protoplasm is less. " It is, however, made equal and 

 equivalent to the latter (Ranvier's) by adding very dilute ammonia 

 to the picric acid solution until it begins to assume a rich wine-red 

 shade which is quite distinct from that of the acid solution." 



The article also contain notes (1) on alcohol, in which it is stated 

 that absolute alcohol is an unnecessary extravagance, 96 per cent, 

 being entirely sufficient for all manipulations ; (2) on benzole which 

 can be used to replace the much dearer xylol, and (3) on imbedding 

 in celloidin (cf. ante, p. 164). 



Eau de Javelle.t — Dr. J. H. List, on making serial sections of 

 Orthezia cataphracta West., experienced unusual difficulties owing to 

 the brittleness and inequalities of the chitinous investment. To 



* Zeitschr. f. Wiss. Mikr., iii. (1886) pp. 173-8. f Ibid., p. 212. 



