APPEARANCES OF THE RED BLOOD-CORPUSCLES., 155 
the two phenomena, so essentially similar in character. I then 
instituted a series of experiments with solutions of different 
salts and various reagents, under different conditions, with a 
view to ascertain the laws which regulate these appearances. I 
subsequently found that the same processes in the red corpuscles 
of the blood of man had been described and figured some years 
previously by Dr. William Addison, F.R.S.! The results I ob- 
tained myself agreed in the main with those described by him. 
It is sufficient here to mention that I found they occurred most 
readily, in the blood of mammals, when treated with a mixture of 
one part of pale sherry wine and one part of a 10-per cent. solu- 
tion of sod. sulph., at a temperature of about 98° Fahr., or 
somewhat lower. The sp. gr. of this mixture is about 1°008, 
and its reaction acid; on neutralisation it fails to produce any 
processes from the red corpuscles. In an aqueous solution of sugar 
2°5 per cent. sod. sulph. 10 per cent., alch. 15 per cent., and ac. 
acet. 1 per cent., they are alsoreadily formed at about the same tem- 
perature. By treatment with some sherry wines alone they are pro- 
duced, though not very readily. A slight acidity of the reagent 
usually favours their production, as does the addition of 10 to 15 
per cent. alcohol ; though neither of these is absolutely essential, 
and the variety of reagents and mixtures which produce them is 
endless. According to the sp. gr. of the solution in which they are 
produced, the temperature, and other circumstances, their form 
and duration is modified. The temperature most favorable for 
their production, in the larger number of cases, is somewhat 
below 98° Fahr., and that in all the mammalia that I have ex- 
amined alike ; above that temperature they are quickly dissolved, 
and much below it,with most reagents, they are formed slowly and 
imperfectly, if at all. A solution of urea, as first stated by Kol- 
liker, and others after him, will produce these appearances in 
the blood both of frogs and of mammals. This is most 
readily effected by drying a drop of the solution upon a slide, 
putting the blood upon this, and covering it. Salt solution, 
0°6 per cent., as described in a recent paper, produces these 
appearances well in defibrinated frog’s blood on the warm stage. 
By this treatment, too, the nucleus of the red corpuscle is some- 
times very clearly shown, and the reticular fibres which it con- 
tains, with the limiting membrane which encloses it, in places 
penetrated by the fibres, as recently described and figured by 
Dr. Klein? in this Journal, and by Fleming,’ are very apparent. 
1 This Journal, N.§., vol. i, 1861, pp. 81—89, and ‘ Proc. R. Soc.,” 
vol. x, 1859, pp. 186—189. 
2 Vol. xviii, N. S., 1878, pp. 814—339, and vol. xix, N. S., pp. 125— 
175, and ib. pp. 404—420, 
3 ‘Archiv fiir Mikros. Anat.,’? Bd. xvi, 1879, s. 302—436, Bd, xviii, 
1880, pp. 151—259, : 
