The Conservation Analytical Laboratory of the Smithsonian Institution
analyzed selected bloodletting instruments and one drawing from the
Museum's collection. Instruments were chosen on the basis of their unique
appearance and as representative examples of the major types of
instruments in the collection. Six lancets and cases, two scarificators,
and one pen and ink drawing were analyzed.
[Illustration: FIGURE 23.--Patent model, J. Ives, 1849. (NMHT 89797
[M-4292]: SI photo 73-4211.)]
[Illustration: FIGURE 24.--Patent model, Reinhold and Schreiber, 1880.
(NMHT 89797 [M-4327]; SI photo 73-4210.)]
X-ray fluorescence analysis, response to a magnet, reaction to nitric
acid, and the Vickers pyramid hardness test were among the methods of
analysis used that involved no damage to the objects.
The instrument for X-ray fluorescence analysis has been modified to permit
analysis of selected areas on the objects. This instrument produces,
detects, and records the object's X-ray fluorescence spectrum, which is
characteristic of its composition. X-rays produced by a target in the
instrument strike the object and cause it, in turn, to fluoresce, or emit,
X-rays. This fluorescence is detected by a silicon crystal in the detector
and dispersed into a spectrum, which is displayed on an oscilloscope
screen. The entire spectrum--from 0 to 40 Ke V--can be displayed or
portions of it can be expanded and displayed at an apparently higher
resolution that permits differentiation between closely spaced fluorescent
peaks, such as those from iron and manganese. The spectrum may be
transferred from the oscilloscope to a computer for calculation of the
percentage of composition and for comparison with spectra of other
samples. During analysis the objects can be supported and masked by sheets
of plexiglas or metal foils to limit the radiation to a certain area of
the object. Masks also prevent scattering of radiation off other parts of
the object and off the instrument itself, which otherwise might be
detected and interpreted as less concentrated components in the object.
Brass was the most common metal used in the fabrication of eighteenth- and
nineteenth-century lancets and scarificators. Upon analysis the brass was
found to contain 70%-75% copper, 20%-30% zinc, and other trace elements.
The blades, cocking levers, and button releases of lancets and
scarificators were found to be made of ferrous metal (iron or steel). In
addition to the typical brass pieces, a number of "white metal" pieces
were analyzed. (The term "white metal" is used to designate any
undetermined silver-colored metal alloy.) Those white metal pieces dating
from the eighteenth century (a Swiss or Tyrolean fleam and an English
veterinary spring lancet) were found to be composed entirely of ferrous
metal. The hardness of the fleam metal indicated that it was carburized
sufficiently to be made of steel. Two of the spring lancets, dating from
the late nineteenth century, were found to be made of a silver-copper
composition that was not rich enough in silver to be sterling silver.
These lancets were probably typical of the lancets advertised as silver in
the late nineteenth-century trade catalogs. About 1850 an alloy imitating
silver began to be widely used in the making of surgical instruments. This
was German silver or nickel-silver, an alloy containing no silver at all,
but rather copper, zinc, and nickel. A patent model scarificator dating
from 1851 was found to contain about 63% copper, 24% zinc, and 13% nickel.
This alloy is presently called "nickel-silver 65-12" alloy. The French
made scarificators out of their own version of nickel-silver that was
called "maillechort." The French circular scarificator was found to
contain copper (55%-70%), nickel (10%-20%), zinc (20%-30%), and tin (less
than 10%). The cases in which the lancets and scarificators were carried
were covered with leather, despite the fact that several appeared to be
covered with paper. X-ray analysis revealed that several cases contained
tin, leading to the possibility that a tin salt was used in the
dye-mordant for leather. The clasps on the cases were made of brass. One
case was trimmed in gold leaf.
The most difficult item to analyze was the pen and ink drawing in black
and red of a bloodletting man purported to be a fifteenth-century specimen
(1480) from South Germany. The text is in German (Figure 25).
The watermark of the paper--a horned bull (ox) with crown--is believed to
have appeared in 1310 and was used widely for two hundred years. The paper
was heavily sized and no feathering of the black ink or red paint appears.
The paper fluoresced only faintly under ultraviolet light and much less
brightly than new paper, leading to the conclusion that the paper is not
modern. Various stains on the paper fluoresce yellow, which also indicates
a considerable history for the document.
The guard strip is vellum. Red stains on this strip may have been made by
blood.
The inks (brown and red) may have come from different sources or been
applied at different times because of their various compositions and
densities. Iron and lead were found in an area of writing on the left
foot. Iron is typical of an iron gall ink. Some of the lighter lines
contain graphite. The red lines contain mercury and lead suggesting a
mixture of vermilion and red lead.
Analysis of the ink and paper indicates that the document has had a varied
history and seems not to have been a deliberate production intended to
simulate age.