2722 Journal of Applied Microscopy 



squeezing, and as lightly as you would draw a camel's hair brush to dust the 

 surface of a lens. The object is to make a thin smear. It is a good plan to 

 make a dozen smears, aud dry them at room heat under cover." The smears 

 are fixed in the following fluid, on which, in large measure, the success of the 

 process apparently depends : 



Sublimate, - - - - - -78 gr. (xvii gr.) 



Sodium chloride, - - - .28 gr. ( iv gr.) 



Distilled water, - - - - 30 c. c. ( i oz.) 



Dissolve and filter. 



" One minute's application of this solution makes a perfect fixative for spleen 

 smears, without producing the slightest distortion of the red blood corpuscles, 

 or the least impairment of their staining properties. They are then stained half 

 an hour in watery solution of alum hsematoxylin, washed, and counterstained 

 from two to three minutes in a 3 per cent, watery eosin. These directions if 

 carefully followed will be found to give perfect results." The preparations so 

 made should be dried and examined without a cover-glass. With the immersion 

 lens a low power ocular should be used till a corpuscle containing a nucleus is 

 found. It may then be studied with a high power ocular. r. p. 



Technique for Dense Connective Tissue. ^'- ^- R^tterer gives an account in a 



recent number of the Journal de 

 I'Anatomie (Ann. 3!), pp. 196, 1903) of the technique which he has developed in 

 his work on the histology of the skin. It is of course well known that tissues 

 containing a large amount of dense connective tissue are very troublesome 

 objects for the microtomist. Retterer says that the things to be avoided in deal- 

 ing with such tissues are too long a stay of the object in the alcohols, and too 

 high a temperature at the time when the tissue is transferred to paraffin. His 

 procedure in detail is as follows : Pieces of skin which have been fixed in either 

 Flemming's, Zenker's, or Branca's fluid and have been washed are dehydrated 

 in 90 per cent, alcohol (1 hour ca.) and absolute alcohol (j4 hour ca.). The 

 tissue is next passed to xylol (20 minutes), followed by a mixture of xylol and 

 36° paraffin (30 minutes at 20°). It is then left for a quarter of an hour in 36° 

 paraffin maintained at a temperature of 40°, an aspirator aiding in the infiltra- 

 tion. The tissue is then embedded in 54° paraffin in the following way: The 

 paraffin in the embedding dish is allowed to set all around the edges and bottom 

 of the dish, while a portion in the center is kept liquid. The tissue is placed in 

 this melted portion and the whole allowed to cool, which it will do in about ten 

 minutes. The tissue may be left in the block for some time before cutting, with- 

 out injury to the histological elements. The author states that in all his experi- 

 ence he has never had a failure with the method. r. p. 



A Method of Making Frozen Sections of I" the Journal of Anatomy and Phys- 

 the Head. iology (Vol. 37, p. 106, 1903) Prof. 



Symington describes a method which he has used with marked success in making 

 macroscopic sections of a frozen human head. The entire body was hardened 

 by the injection of a strong solution of formalin. The neck was divided opposite 

 the fifth cervical vertebra and the head again injected with a solution of gum, 



