20 
On Changes of Form in the Red Corpuscles of Human 
Blood. — By William Addison, M.D., F.R.S. 
(Communicated by Dr. Lankester. Read December 12th, 1860.) 
When freshly drawn, human blood is examined with a 
microscope, the form in which the red corpuscles appear is well 
known. The greater part of these bodies adhere together in 
rolls, a few floating singly in the blood-fluid, or liquor 
sanguinis. 
(Plate III, fig. 1.) We may call this form the normal form. 
But occasionally, without anything having been added to the 
blood, the forms depicted as alkaline forms (fig. 2) may be 
seen. 
These rough or prickly forms (fig. 2) are with certainty 
produced by fresh urine, by a weak solution of common salt, 
and by various liquids rendered slightly alkaline with solution 
of potash. On the other hand, the forms represented in fig. 3 
are determined by adding to the blood a solution of sugar 
and liquids rendered feebly acid by hydrochloric acid, or by 
lemon or orange juice. 
The tailed forms (fig. 4) occur when blood is submitted to 
the action of sherry wine. 
Make a saline solution by dissolving one grain of common 
salt in two fluid drachms of water, and render it very slightly 
alkaline with solution of potash; also dissolve four grains 
of refined sugar in two fluid drachms of water, and render it 
slightly acid to litmus paper with the diluted hydrochloric 
acid of the London Pharmacopoeia. 
Receive a small drop of fresh blood upon a slip of glass, and 
place near to, but not touching it, a similar amount of the 
saline alkaline solution ; also place in a like manner, on the 
other side of the blood, an equal quantity of the acid-sugar 
solution; drop down upon the three fluids a thin piece of 
glass, so that the alkaline fluid may come into contact with 
one side of the drop of blood, and the acid fluid into contact 
with the opposite side of it. 
Upon examination with the microscope, the forms of the 
corpuscles which float out into the alkaline fluid will be found 
quite diff'erent from those which float out into the acid fluid. 
Those in the alkaline fluid have roughened outlines (fig. 2), 
whereas those in the acid liquid have smooth outlines, and a 
bright matter, of sundry forms, makes its appearance in their 
interior (fig. 3) . If the corpuscles be followed as they continue 
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