SINCE PREYER'S INVESTIGATIONS. 117 



In the second contribution referred to, Halliburton adds the following 



to our crystallographic data: 



Opossum (Didelphis cancrivora). Very large dark crystals can readily be obtained. They 

 belong to the rhombic system. 



Kangaroo (Macropus giganteus). Crystals are more soluble, and so less readily obtained. 

 They are rhombic prisms, slenderer than in the opossum. 



Sugar squirrel (Belideus breviceps a marsupial). Crystals similar to those of opossum. 



Seal (Phoca vitulina) . Rhombic prisms, many of them very short and simulating hexa- 

 gons. Easily obtained. 



Bear (Ursus syriacus). Bunches of rhombic needles, easily obtained. They are slen- 

 derer than those obtained from dog's blood, as a rule, some being almost silken in 

 appearance. 



White-bellied beaver rat (Hydromys leucogaster) . Rhombic prisms. 



White-whiskered swine (Sus leucomytax). Rhombic prisms. 



Water vole (Arvicola aquatica). Crystals are obtained easily by adding water to the 

 blood. They are of the usual rhombic shape. 



The analyses of hemoglobin of horse's blood by Zinoffsky (loc. cit.) 

 differed so much from those of previous observers that Hiifner (Beitrage z. 

 Physiologie, Fest. f. Carl Ludwig, 1887, 74) was led to review and supple- 

 ment Zinoffsky's work. Hiifner prepared hemoglobin crystals by a process 

 that is a modification of Zinoffsky's to the extent essentially of separating 

 the stromata of the corpuscles by mechanical instead of chemical means, 

 that is by centrifugalization, so that the crystals could be freed from the 

 stromata dissolved or undissolved and more expeditiously prepared. Crys- 

 tals were obtained from the bloods of the pig and ox by centrifugalizing the 

 corpuscles, extracting the hemoglobin from them by distilled water at 30 

 to 40, cooling to 0, centrifugalizing and treating by the usual method. 

 After the crystals have formed they are centrifugalized in the cold to pre- 

 vent their solution, and the hemoglobin is then three times crystallized by 

 the usual method, and finally dried in an atmosphere at 0. The ash of 10 

 grams of this product contained only an imponderable amount of phosphoric 

 acid. The mean figures of his elementary analyses are as follows: 

 Pig's oxyhemoglobin, C54. 71 H 7 .3 8 N 17 .43So.479 Fe o-3390i9-602 

 Ox's hemoglobin, C 54 . 66 H 7 . 25 N 17 . 76 So.447Fe .4oOi9-543 

 In comparing these figures with those of Otto (loc. cit.}, Hiifner states that 

 the complete removal of the stromata in his preparations causes a higher 

 percentage of C and N, Otto having found C 54 . 17 and N 16 . 23 . Zinoffsky's C 

 content (51.15) was very much lower than Hiifner's. Hiifner's analyses 

 show the same ratio of S and Fe in both pig and dog hemoglobins, i.e., 2 

 of sulphur to 1 of iron, the same as Zinoffsky found with horse hemoglobin. 

 The elementary analysis of the hemoglobin of the dog which was 

 reported the following year by Jacquet (Zeit. f. physiol. Chemie, 1888, 

 xn, 285) was of crystals prepared as follows: The corpuscles were centri- 

 fugalized, then mixed with 2 volumes of water warmed to 35, then cooled 

 and shaken with ether and treated according to the Hoppe-Seyler process. 

 The crystals were twice recrystallized, and then analyzed according to the 

 methods pursued by Zinoffsky, but he endeavored to eliminate certain 

 possible fallacies in the iron determinations. His analyses gave a mean 



