^Sauseptri£T Corpuscles in Blood-stains. 149 
ful American microscopists, gives, as the result of his experiments 
upon dried blood : * — " If a drop of blood be rubbed on a piece of 
glass, as by drawing a bloody finger across it so that the disks are 
deposited in a singfle layer, and then allowed to dry, they are readily 
recognized even in the dried state ; but when allowed to dry in 
masses, I have failed to determine their presence. The lymph 
globules, on the contrary, may be softened out after they have been 
dried for months, and their characteristic marks readily obtained." 
And Prof. Yirchow, of Berlin, observes : t — " In regard to the 
diagnosis by this method (difference in size of the blood globules in 
mammalia), I can only endorse the unfavourable opinion of Briicke, 
and I do not believe that any microscopist will hold himself justified 
in putting in question a man's life on the uncertain calculation of a 
blood corpuscle's ratio of contraction by drying." 
One of the primary steps in entering upon an investigation of 
blood-stains is the selection of a proper menstruum for moistening 
the dried clot, and here at the outset we meet with a great dis- 
crepancy of opinion ; by some authorities pure water, which cer- 
tainly has the advantage of far greater convenience in its employ- 
ment, is highly recommended, whilst others who prefer saline 
solutions, fixed or volatile oils, &c., condemn the use of water as 
utterly destructive to the red corpuscles ; thus, M. Ch. Eobin, of 
Paris, in a translation of one of his articles on the subject in the 
' New Orleans Medical News,' December, 1857, is credited with the 
following statement : — " By scraping the small crust (of a blood- 
stain), as seen under a simple magnifying glass, and receiving it 
either in the shape of dust or small fragments, under the ordinary 
glass object-carrier, we found that water discoloured (decolourized ?) 
the spots or the substance taken up by scraping, that the latter 
takes a greyish hue and swells up a little ; the water, on the other 
hand, becomes slightly red, takes up the colouring matter of the 
red globules of blood, dissolves the colourless elements, and leaves 
after this action no visible particles behind, such as nucleus or 
granulations." Prof. Kobin declares the residuary grey mass to be 
" composed entirely of fibrin." 
This opinion in regard to the action of water on the red discs 
seems to be one widely accepted at present, for we find Prof. Austin 
Flint, jun., of New York, observes, on p. 116 of the first volume of 
* The Physiology of Man,' published in 186(3 : — " If pure water be 
added to a specimen of blood under the microscope, the corpuscles 
will first swell up, become spherical, and are finally lost to view by 
solution;" and Prof. Lionel Beale teaches, on p. 169 of the 
* Microscope in Practical Medicine,' that the red corpuscles are 
simply " masses of soft viscid matter, perhaps of the consistence of 
* Beiui'a ' Report of the Websltv Case,' p. 91. 
t Virchow's ' Archiv./ band, xii., s. 1)36. 
