194 H. £M0 GL OB IN. 
which is sparingly soluble in dilute alcohol, especially at low tempera- 
tures, to crystallise. In the case of animals, the haemoglobin of whose 
blood is very sparingly soluble, the addition of alcohol or ether is often 
dispensed with. We shall, in the first place, describe those methods 
which readily furnish haemoglobin crystals for the purposes of micro- 
scopical research, and then the methods which are employed for the 
preparation and purification of large quantities of haemoglobin. 
Methods employed in preparing small quantities of haemoglobin 
for microscopic examination. — 1. Funke's method} — From the blood of 
those animals whose blood crystallises readily, but especially in the 
case of the rat, oxyhemoglobin can be obtained for microscopic exami- 
nation in three or four minutes, by receiving a drop of blood on a 
glass slide, adding a drop of distilled water, mixing the two liquids 
by means of a needle, and spreading the mixture over the central part 
of the slide. When the edges of the liquid commence to dry, cover 
with a microscopic covering glass. Crystals of haemoglobin form at 
once. 
2. Rollett's method? — A platinum capsule is placed in a freezing 
mixture, and freshly defibrinated blood is poured into it, so as to convert 
it into a lump of red ice. After being in the freezing mixture for half 
an hour the blood is allowed to thaw gradually, and the contents of the 
capsule are poured into a glass vessel of such dimensions that the 
bottom is covered by the lake-coloured blood to a depth of 15 mm.; 
the glass vessel is then set aside in a cool place. In a short time, 
the blood of rats, of guinea-pigs, and of sejuirrels, treated by this method, 
furnishes well-formed crystals. 
3. Gscheidlen's method. 3 — Defibrinated blood, which has been exposed 
to the air for a period of twenty-four hours, is sealed in narrow glass 
tubes (vaccine tubes answer well), and these tubes are then placed in 
the incubator and kept a temperature of about 37° C. for some days. 
On opening the tubes and emptying their contents into a watch glass or 
on a glass slide, and allowing some time for evaporation to take place, 
crystals of extraordinary size are obtained. 
4. Max Schultze's method* — Defibrinated blood is heated (on a warm 
stage, in the case of a microscopic preparation) to a temperature of 60° F., 
when the corpuscles dissolve and the blood becomes lake-coloured ; it 
is then allowed slowly to cool and to evaporate. This method may be 
employed with large quantities of blood, and Preyer 5 found that by no 
other method did he obtain as fine and as large crystals from horse's 
blood. 
In addition to the four methods which have been above described as 
most conveniently yielding crystals of oxyhemoglobin, when these are 
desired on a small scale, there are many others which have been employed, 
and which occasionally give good results. 
Thus Piollett 6 found that when induction shocks were passed through 
blood, it became lake-coloured and yielded crystals of haemoglobin, and 
1 Ztschr.f. rat. Med., 1851, S. 185. 
2 "Versuche und Beobachtungen am Blute," Sitzungsb. d. Jc. Akad. d. Wissensch.. 
Wien, 1863, Bd. xlvi. S. 77. 
3 Arch./, d. ejes. Physiol., Bonn, 1878, Bd. xvi. S. 421. 
4 "Em heitzbarer Objecttisch und seine Verwendung bei Untersuclnuigen des Blutes," 
Arch.f. mikr. Anat., Bonn, 1S65, Bd. i. S. 31. 
5 ''Die Blutkrystalle," S. 23. 
6 Sitzungsb. d. k. Akad. d. IFisscnsch., Wien, 1852, Bd. xlvi. S. 75. 
