PREVIOUS TO THE INVESTIGATIONS OF PREYER. 87 



Bursy (Inaug. Dissert., Dorpat, 1863; Ber. ii. d. Fort. d. Anatomie u. 

 Physiologie, 1862, 293) studied the influences of various salts upon the 

 crystallizability of hemoglobin. He found that sodium sulphate, sodium 

 phosphate, sodium acetate, magnesium sulphate, and potassium sulphate 

 favor crystallization; that potassium carbonate, potassium sulphate, 

 sodium borate, barium nitrate, and sal ammoniac have little favorable 

 effect; that sodium chloride, ammonium nitrate, calcium chloride, and 

 alum were without influence; and that sodium nitrate appeared to hinder 

 crystallization. 



Ankersmit (Inaug. Dissert., Groningen, 1863; Ber. ii. d. Fort. d. Anat. 

 u. Physiologie, 1863, 268) prepared crystals from human venous blood, 

 which crystals he found became decolorized under certain conditions, and 

 he therefore believed, as did Lehmann and others before him, that the 

 crystals are only mechanically colored or stained. Klebs (Centralblatt f. 

 med. Wissensch., 1863, i, 268) reports having found crystals in the cor- 

 puscles of the guinea-pig, rabbit, pig, sheep, and bullock, and also in man. 

 Kiihne (Centralblatt f. med. Wissensch., 1863, i, 851) recorded a process 

 for preparing hemoglobin crystals by the addition to the blood of bile salts. 

 He prepared in this way crystals from the blood of the horse and dog. In 

 a later article (Archiv f. path. Anat. u. Physiologie, 1865, XLIII, 423) he 

 states that he prepared crystals of reduced hemoglobin from the blood of 

 the dog. He also noted the fact that the alkaline serum hinders the crystal- 

 lization of hemoglobin. Valentine (Untersuch. z. Naturlehre, etc., 1863, 

 ix, 129) obtained crystals from the blood of a marmot that had been hiber- 

 nating for a long time. 



At this time (1863) there still existed much difference of opinion as to 

 the exact nature of the blood crystals, and Bojanowski (Zeit. f. wissensch. 

 Zoologie, 1863, xn, 312), in going over certain unsettled points, concluded 

 that only the contents of the corpuscles participate in the formation of the 

 crystals, that the crystals are merely stained, and, therefore, that the name 

 given by Kolliker, "globulin crystals," is entirely justifiable. His reasons 

 for reaching this last statement were based partly on the reports of Leh- 

 mann, Teichmann, and others of having obtained decolorized crystals, 

 and partly from his own experience. He states that if the blood crystals 

 are allowed to stand for a time in the air they always retain their form, but 

 become clearer and clearer, and finally completely colorless and transparent. 

 The same is observed if to the crystals is added a strong sugar or gum 

 solution. 



Bojanowski prepared crystals from the blood of man, and from the 

 rabbit, mouse, dog, cat, hedgehog, river bream, pike, horn-fish, herring, 

 lark, raven, and pigeon. Crystals of human blood he obtained from the 

 stomach of the leech, and also from venous blood. The latter was 36 hours 

 old, and crystallization was completed within 3 to 4 hours without anything 

 being added. The addition of water causes crystallization, but more spar- 

 ingly and irregularly; but on the addition of alcohol and ether he failed 

 in 15 experiments to obtain crystals. Crystals of the river bream he ob- 

 tained without any treatment of the blood, and he states that this blood 



