2
merely as a matter of historic interest, 1 a n d n o w I s e e t h a t U h l e n h u t h a n d
Weidanz 2 s e e m t o t h i n k t h a t t h e r e i s r e a l l y s o m e t h i n g t o b e s a i d f o r i t , b u t
that its merits depend on the observer's keen sense of smell, and therefore do not
warrant its use in medico-legal practice. So slowly does an erroneous observa-
tion die in medico-legal circles, the reason being, I think, that the legal type of
mind, as distinguished from the medical type, is prone to accept, unquestioning,
the statements of authority.
In 1862 Erpenbeck 3r e p o r t e d t h a t t h e m e r e h e a t i n g o f a b l o o d - s t a i n t o n e a r
charring point in a test-tube would enable one to fix the source of the blood that
had caused it, by the odour evolved; but here, too, careful investigation showed the
utter worthlessness of the "test".
As it appeared that Chemistry was powerless to aid the medico-legists in
their endeavour to fix the source of blood-stains, they had recourse to the micro-
scope, technique having become much improved; and at one time it seemed as
if careful micrometric measurements were all that one needed to be able to
distinguish with certainty between human and other mammalian red blood-corpuscles.
Soon, however, doubts were expressed, by so great an authority as Virchow 4
as to the possibility of fixing the drying coefficient of the cells. Further observa-
tion seemed to set these doubts at rest: Virchow in 1875 published a report by
Malinin 5o f t h e a c c u r a c y o f m i c r o m e t r i c d i f f e r e n t i a t i o n o f b l o o d - c e l l s .
Richardson in 1874 6 was loud in his praise of this method of diagnosis; but
he had to admit7 t h a t h e " w a s a w a r e o f t h e i m p o s s i b i l i t y o f d i s t i n g u i s h i n g t h e
blood of a man from that of a dog, but refrained from giving prominence to these
facts, lest an improper use should be made of them in the defence of criminals".
A strange and, I think, almost unique instance of a man of science having his soul
vexed by thoughts of the possible effect of his discoveries.
1 DRAGENDORFF:—Untersuchung von Blutflecken. in Maschkas Handbuch der gear. Medicin
Tübingen, 1881-82.
2 UHLENHUTH and WEIDANZ:—Praktische Anleitung zur Ausführung des biologischen
Eiweissdifferenzierungsverfahrens mit besonderer Berücksichtigung der forensischen Blut- und
Fleischuntersuchung, sowie der Gewinnung präzipitierender Sera. J e n a
1 9 0 9 .
3 ERPEN BECK:—Ueber chemische und microscopische Untersuchung auf Blutspuren in
Criminalfällen. Viertcljahrschr. f. ger. Med. 1862, xxi, 15,250.
4. VIRCHOW:—Ueber die forensische Untersuchung von trockenen Blutflecken. Arch. f. path.
Anat. 1857, xii, 334.
5 MALININ:—Ueber die Erkennung des menschlichen und thierischen Blutes in trockenen
Flecken in gerichtlich-medicinischer Beziehung. Ibid. 1875, lxv, 528.
6 R ICHARDSON:—On the value of high powers in the diagnosis of blood-stains. Amer. journ.
med. sci . 1874, 68, 102.
Note on the diagnosis of blood-stains. Monthly microscop. journ 1875, xiii, 213.
7 WOODWARD:—On the similarity between the red blood-corpuscles of man and those of certain
other mammals, especially the dog—considered in connexion with the diagnosis of blood-stains in.
criminal cases. Ibid. 1875, xiii, 65.