1902] MICROSCOPICAL JOURNAL. 27 
preserves nuclearand protoplasmic structures excellently. 
For imbedding, the celloidin method is better adapted 
than the paraffin method. Photoxylin is a new substance 
which is used in the same way as celloidin, dissolves im- 
mediately, is more transparent and is less stained by 
hematoxylin. In the form of wool, photoxylin is very 
explosive, dissolves in alcohol and ether mixed and ab- 
sorbs water from the air. 
Weigert invented and Obregia has modified a method 
of obtaining serial sections from celloidin imbedded ma- 
terial and this the author describes at length. 
Work with hematoxylin is, of course, considered in 
great explicitness. As this stain may be easily overdone, 
directions are given for the treatment of overstained sec- 
tions, such as by the use of ammonia-alum, or of one-tenth 
per cent hydrochloric acid. A beautiful counter stain is 
got in using an excess of hematoxylin and following with 
weak nitric acid and weak liquor potassz to produce a 
bright blue. Tripple staining may also be secured with 
Van Gieson’s stain or by the Biondi-Heidenhain method. 
The former produces brownish-yellow, bright red and 
violet; the latter, blue, green and red. As expected, 
double staining with carmine is done in several ways. 
Safranin also gives important results. 
Among the special stains for special tissues are de- 
scribed: Weigert’s stains for medullary sheaths; Pal’s 
stain for the same; Marchi’s method for same; Nissl’s 
‘stain for ganglion cells; Weigert’s stain of neuroglia; 
the orcein process for elastic fibres; Heidenhain’s demon- 
stration of karyomitotic figures; and Benda’s iron-ha- 
matoxylin method. 
A most valuable chapter relates to the demonstration 
of definite substances and tissue elements, such as fatty 
degeneration, calcareous degeneration, cholestearin, mu- 
coid, hyaline, and amyloid degenerations, fibrin, iron, 
copper and mercury in the eye. 
