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CARTILAGENEOUS TISSUE. 549
the excess of this acid removed with sugar of lead, and the lead removed
from the filtrate by H2S. If further purification is necessary, the acid is
precipitated with alcohol, the precipitate dissolved in water, this solu-
tion dialyzed and precipitated again with alcohol—this solution in water
and precipitation with alcohol being repeated a few times—and lastly
the acid is treated with alcohol and ether. Other methods for the prepara-
tion of the acid (from the septum narium of the pig) have been suggested
by Schmiedeberg and Kondo.
The collagen of the cartilage gives, according to C. Morner, a gelatin
which contains only 16.4 per cent N, and which can hardly be considered
identical with ordinary gelatin.
In the above-mentioned cartilages of full-grown animals the chon-
droitin-sulphuric acid and chondromucoid, perhaps also the collagen,
are found surrounding the cells as round balls or lumps. These balls
(Morner’s chondrin-balls) , which give a blue color with methyl-violet,
lie in the meshes of a trabecular structure, which is colored when
brought in contact with tropseolin.
The albumoid is a nitrogenized body which contains loosely com-
bined sulphur. It is soluble with difficulty in acids and alkalies and
resembles keratin in many respects, but differs from it by being soluble
in gastric juice. In other respects it resembles elastin, but differs from
this substance in containing sulphur. This albumoid gives the color
reactions of the protein bodies.
Cartilage gelatin and the albumoid may be prepared according to
the folowing method of Morner: First remove the chondromucoid
and chondroitin-sulphuric acid by extraction with dilute caustic potash
(0.2-0.5 per cent), remove the alkali from the remaining cartilage by
water, and then boil with water in a Papin’s digester. The collagen
passes into solution as gelatin, while the albumoid remains undissolved
(contaminated by the cartilage-cells). The gelatin may be purified by
precipitating with sodium sulphate, which must be added to saturation
in the faintly acidified solution, redissolving the precipitate in water,
dialyzing well, and precipitating with alcohol.
In Morner’s experience no albumoid is found in young cartilage,
but only the three first-mentioned constituents. Nevertheless, the young
cartilage contains about the same amounts of nitrogen and mineral
substances as the old. The cartilage of the ray (Raja batis Lin.), which
has been investigated by Lonnberg,1
contains no albumoid and only
a little chondromucoid, but a large proportion of chondroitin-sulphuric
acid and collagen.
According to Pfluger and Handel,2
glycogen occurs to a slight
1
Maly’s Jahresber., 19, 325.
1
Pfluger in Pfliiger’s Arch., 92; Handel, ibid.
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