Lakhasly

Th e history of formalin dates back to the Age of Enlightenment when medieval alchemy, steeped in magic and astrology, slowly gave birth to chemistry, its modern off spring.Ancient lore was evolved into scientifi c understanding by scientists like German-Swedish chemist Carl Wilhelm Scheele who discovered a number of elements and compound.Its synthesis was described later in the 18th century by the French scientists Antoine Francois Fourcroy and Louis Nicolas Vauquelin, who isolated it in the course of their experimental research on sulfuric acid.It should be remembered that a little of the fl uid must remain at the bottom of the jar, so the preparations are constantly under the infl uence of at least a minimal amount of formol vapor.Aft er a further 8-14 days preparations can be removed and stored in a glass jar with a glass stopper.On the second or third day aft er this, the contaminated fl uid is changed once.In 1777, he discovered the substance that came to be known as acetaldehyde [2].

Th e history of formalin dates back to the Age of Enlightenment when medieval
alchemy, steeped in magic and astrology, slowly gave birth to chemistry, its modern
off spring. Ancient lore was evolved into scientifi c understanding by scientists
like German-Swedish chemist Carl Wilhelm Scheele who discovered a number
of elements and compound. In 1777, he discovered the substance that came to be
known as acetaldehyde [2]. Its synthesis was described later in the 18th century
by the French scientists Antoine François Fourcroy and Louis Nicolas Vauquelin,
who isolated it in the course of their experimental research on sulfuric acid. While
studying the oxidation of alcohols in 1835, Justus von Liebig categorized acetaldehyde
as a “dehydrogenated alcohol” and calling it at the time “aldehyde” [3]. With this
growing understanding of aldehyde chemistry, Alexander Butlerow became the fi rst
to synthesize formaldehyde in its gaseous form and as a polymer in solution in 1859
[4, 5]. Nine years later, in 1868, August Wilhelm Hofmann, proposed a simplifi ed
method of producing formaldehyde from methanol and determined its molecular
structure [6].
As scientists discovered the properties of formaldehyde, industrial engineers
of the time quickly developed commercial applications for it as well. Th is led to
a demand for large amounts of the compound and by 1891 the fi rst patent for a large
scale production process was obtained in Germany [7]. Production of formaldehyde
solutions quickly spread to other countries in Industrial Revolution-era Europe. Th ese
commercially-produced solutions varied significantly in concentration and other
ingredients and bore a variety of names. In England it was usually called formic acid.
In Germany we fi nd formol and formalin, the term also widely used in the United
States. In some countries, formaldehyde was sold under the trademark Formal [7]
With this increase in industrial production, these various solutions became less
expensive and more available to scientist as well.
As more scientist gained access to formaldehyde, medical applications for the
compound were gradually discovered. Between 1880 and 1890 its antiseptic properties
were recognized [8], leading to promising tests of clinical applications [4]. In 1892, the
French scholar Jean Auguste Trillat observed formaldehyde hardening soft tissues and
triggering coagulation [9]. Th e following year Ferdinand Blum, working intensively
on the use of formaldehyde solution in antiseptic procedures, reported that the skin
of the fi ngertips became visibly thickened aft er prolonged exposure, having become
impregnated [10, 11].
Applications for these preservative properties of formaldehyde were quickly
recognized and by the mid-1890s some scientists were already experimenting
with various solutions in anatomical and histological preparations [12]. An earlier
pioneer was the German physician and biologist Ferdinand Blum who compared
the eff ectiveness of formaldehyde to that of traditionally-used preserving agents such
as alcohol [13]. By 1896, Blum had shown that formaldehyde was more eff ective at
maintaining the color and shape of tissues without aff ecting the microscopic structure
of the preparation [14, 15]. Blum’s results were confirmed by Ferdinand Julius Cohn (Fig. 1), Frederick
C. Kenyon, by his own father, Isaac Blum and by others [16]. In 1893, Cohn
experimented with a 40% solution of formaldehyde (later to be called formalin) and
confi rmed its antibacterial and fi xative eff ect on internal structure of animal soft
tissues and proteins [17]. Th is was confi rmed by Isaac Blum who at the end of 1893
used 10% and 20% solutions of formaldehyde to preserve diff erent types of tissue in many animal and plant species, including fi sh, amphibians, reptiles, small mammals
and invertebrates, as well as fl owers and fruit. Th e elder Blum also used his solutions
to preserve human embryonic and fetal specimens. Similar work with formalin was
done by Kenyon who published his results in a paper in 1895. In it, Kenyon describes
how he was able to reproduce the results obtained by Blum and other researchers,
supporting formaldehyde’s eff ectiveness in the preparation of various types of animal
tissues. Additionally, he found that even when formalin caused shrinkage of a tissue,
it did not alter its microscopic structure. On a macroscopic scale, he noted that the
shape and color of tissue was preserved with only blood-filled vessels becoming
discolored, that the eyeballs maintained a nearly life-like appearance, and that plant
material could be prepared successfully as well. In his paper, Kenyon also gave
practical guidelines for the use of formalin, including the simultaneous use of alcohol
for fi xing histological sections.
With this proven eff ectiveness and practical guidelines, the use of formalin in
anatomy and histology increased gradually during the mid-1890s. It also became an
essential ingredient in the embalming human bodies. From 1841 to 1879, not one of
the 13 formulas commonly used for embalming fl uids included formalin. By 1899,
this number grew to 25 of 159 registered recipes. From the turn of the century until
1954, formalin was present in 192 of 413 formulas [18]. Th is increase in formalin use
was helped by further improvements in the manufacturing process such as a process
of producing formaldehyde from methanol, developed by the German chemist Oscar
Loew [19]. By 1895, the cost of formaldehyde dropped to below the cost of other
commonly used fi xatives, including alcohol [7]. Before the end of the 19th century,
formaldehyde had mostly replaced alcohol as the main ingredient in anatomical and
histological preparation techniques The use of formalin in Poland was introduced by the surgeon Victor Wehr.
A disciple of another famed Polish surgeon, Louis Rydygier, he described the uses
of the solution during a session of the Seventh Congress of Polish Physicians and
Naturalists held in Lvov in 1894. He presented a number of reports in the scientifi c
literature and described his own uses [20]. Wehr began using formalin in 1893 to
preserve pathologically altered organs and tissues removed during surgical operations.
He was especially interested in structure of tumors. He reported: “resected tumors or
organs are inserted immediately aft er the operation into a 1–2% aqueous solution of
formalin or formol. On the second or third day aft er this, the contaminated fl uid is
changed once. Aft er a further 8–14 days preparations can be removed and stored in
a glass jar with a glass stopper. It should be remembered that a little of the fl uid must
remain at the bottom of the jar, so the preparations are constantly under the infl uence
of at least a minimal amount of formol vapor. In preparations stored in this way I did
not see, even aft er more than half a year, any trace of decay, or destructive bacteria, or
yeast or mold” [20].