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PEOaEESS OF MICEOSCOPICAL SCIENCE. 
Bony Tissue, not prepared Plain, hut with Aniline Dye. — ^M. Ranvier 
—no mean authority on the subject of bone tissue — recommends the 
adoption of the following method in the ' Archives de Physiologic,' 
which is abstracted by the ' Medical Record ' : A portion of the shaft 
of a long bone is procured, and immediately on removal from the body 
is plunged into water. It is allowed to macerate in this for the space 
of a year ; the water in the mean time being repeatedly changed. At 
the end of that time the bone will be found to have become as white 
as ivory, and quite free from any adhering tissue. The object of im- 
mediately plunging the bone in water is to prevent the infiltration of 
the canals and substance of the bone with fat. 
When the bone is thoroughly macerated, sections of it are made 
with a saw. These sections are ground down on pumice-stone, and 
finally polished on a harder material. In order to remove the pow- 
dered fragments of bone which have been ground off from the canals 
and lacunae on the surface, it is sufficient to scrape the section with a 
scalpel. It is then placed in a warm solution of the aniline, and 
allowed to remain there for two hours, and afterwards dried on a 
water-bath. 
The section is next rubbed on a hone, moistened with a 2 per cent, 
solution of common salt. It is then washed in this solution, and per- 
manently mounted in a mixture of equal parts of the solution of salt 
and glycerine. 
In objects prepared in the above manner three important facts, not 
previously noticed, may be observed. 
The first is the existence of lacunae or corpuscles, consisting of a 
simple slit, not much larger than a canaliculus. The fact of their 
being lacunae is proved by the relation in which they stand to the 
canaliculi, which is precisely the same as that of other lacunae. The 
name given to these fine atrophied corpuscles or lacunae is confluents 
lacunaries. They are lacunae either partially or completely atrophied. 
This observation bears out the theory of the disappearance of the 
lacunae with age. But this disappearance is not due to the lacunae 
being filled up with fresh bone, but rather to a process of atrophy. 
The second interesting fact rendered clear by this method is, that 
the canaliculi which are given off from the outer sides of the external 
lacunae of each Haversian system proceed for a short distance as though 
they were going to inosculate with a neighbouring system. They then 
turn on themselves, and inosculate with other canals belonging to their 
own system. These are called canalicules recurrents. From this fact 
we may conclude that each Haversian system forms a complete struc- 
ture by itself, and represents the elementary bone. 
The third fact relates to the structure which intervenes between 
the Haversian system. In transverse section there may be observed, 
in these islets of bone, certain small circles which represent the fibres 
of Sharpey divided transversely. These circles are only to be seen in 
