98 
Iron-haematein Stain 
is desirable. The protoplasm then remains nearly unstained, the 
structure of the tissue-nuclei is shown beautifully, and it deserves 
especial mention, that the limits between the cells in the several 
different types of epithelia are remarkably well defined. 
For histological purposes a combination of this stain with the acid 
fuchsin—picric acid—acetic acid solution of Hansen (1898) gives far 
clearer pictures than the so-called van Gieson’s stain as ordinarily 
employed. It may of course also be combined with any other counter 
stain, just as the ordinary haematoxylin-method, but generally with 
better results, as the protoplasm comes out more sharply in the colour 
of the counter stain, because it absorbs haematein to a much less 
degree than it does haematoxylin. 
I consequently believe, that the staining process will not only be 
a useful substitute for Heidenhain’s method in protozoological work, 
but also that it may take the place of the different haematoxylin- 
combinations in most cases, especially as it is both rapid and easy to 
carry out. However, as to its principal advantages, I may emphasize 
the fact that it gives a good stain in certain cases where no other 
haematoxylin-method can be used, and that it does away with all 
differentiation, a circumstance which adds greatly to the reliability of 
any stain. The rapid execution will be of value especially for work in 
tropical countries, where it is always inconvenient to keep preparations 
for a long time in watery solutions. 
This method certainly does not compete with the Romanowsky 
stains, especially the Giemsa and Leishman methods, which have a 
field of their own in the rapid diagnosis of malaria and other blohd 
diseases, and which have the great advantage of not producing any 
confusion between chromatin and pigment, between which it is some¬ 
times difficult to distinguish in sections stained by iron-baemateiu, or 
haematoxylin. In more detailed work the use of both the Giemsa and 
the irou-haematein-stains will generally be necessary. 
In PI. V some figures are given, which illustrate the results 
obtained. The method may be summarized as follows: 
I. Sections. 
1. Fixation in sublimate-alcohol with ordinary subsequent opera¬ 
tions, embedding in paraffin. 
2. Sections 5 /a in thickness, or less. Sections to be fixed on slides 
without any medium. 
