Biomedical Engineering Reference
In-Depth Information
th
published by the beginning of the 20
century, which indicated to
the importance of this chemical for the human being. To give the
appropriate tribute to those early investigators and restore the
historical perspective, it is worth citing them all [45-66]. One can
see that almost all of these studies were performed and published
by single researchers (see individual comments to Refs. [45, 52]),
while the majority of the investigations were devoted to analytical
chemistry.
In
Chemistry
by Wilson, published in 1850 [67], one can read the
following: “797.
. — There are many compounds
of lime and phosphoric acid, owing to the peculiarity of that acid
in relation to the number of equivalents of base it combines with
at once. The most interesting phosphate of lime is that which
occurs in bones, and is distinguished as the bone-earth phosphate,
3CaO,PO
Phosphates of Lime
.” (p. 219). Thus, various calcium orthophosphates were
already known in 1850. However, the preparation technique sounds
unusual to the modern readers: “The phosphorus combines in part
with the oxygen of the lime, CaO, to form phosphoric acid, and this
with undecomposed lime, to form phosphate of lime, CaO,PO
5
. At the
same time another portion of the phosphorus combines with the
calcium of the lime, forming phosphuret of calcium, CaP.” (p. 164).
In
5
by Brande and Taylor, published in 1863 [68], one
can find the following statements: “Common Phosphate of Lime;
Tribasic Phosphate of Lime; Bone Phosphate; (3(CaO),PO
Chemistry
). —
This salt occurs abundantly in bone-ash, and is found as a mineral
product.” (p. 331). Furthermore, “
5
Native phosphate of lime
(bone
phosphate) occurs in
apatite
,
moroxite
,
phosphorite
, and
asparagus
stone
; its primitive form is a six-sided prism: it also occurs in some
volcanic products.” (p. 332). Thus, a similarity between the inorganic
phase of bones and calcium orthophosphate rocks of natural origin
(apatite and phosphorites) was already known in 1863. “When a
solution of bone-earth in hydrochloric or nitric acid is boiled to expel
all carbonic acid, and decomposed by caustic ammonia, the bone-
phosphate separates in the form of a bulky precipitate, which, when
perfectly dried, is white and amorphous.” (p. 331). This statement is
really astonishing because it might be considered as the first mention
on ACP (Chapter 2), 32 years before Wilhelm Conrad Röntgen
(1845-1923) discovered X-rays in 1895! Furthermore, the presence
of carbonates in bones was already known. Next citation: “The
substance known under the name of
coprolites
, and which appear
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