110 PREPARATION AND CRYSTALLOGRAPHY OF HEMOGLOBINS 



by Stirling and Brito (Jour. Anat. and Physiology, 1882, xvi, 446), by 

 causing the leeches to disgorge. To do this they applied pressure, an 8 

 per cent salt solution, weak to strong acetic acid, 2 to 1000 solution of 

 sulphuric acid, or galvanic or faradic shocks. Within 20 days, hemoglobin 

 crystals appeared, which was much earlier, they state, than was noted by 

 Budge and Bojanowski; but no hemin crystals were found, as were thought 

 by Bojanowski to be present at tunes. Even after a year and a half they 

 found dusky-red purplish crystals of reduced hemoglobin of human blood 

 in the form of 4-sided prisms, some of them nearly equal-sided, while 

 others were oblong. From the stomach of the leech they obtained crystals 

 from the blood of the common gold-fish, and also obtained crystals from 

 sealed microscopic preparations of the diluted fish blood. From the blood 

 of the frog the}' secured both colored and colorless crystals of exactly the 

 same form. The former they describe as being very variable in size, highly 

 refractive, acicular, and pointed at one extremity like the point of a pen. 

 Stirling and Brito note that colorless crystals of frog's blood had also been 

 discovered by Teichmann (loc. cit.), who mixed the defibrinated blood with 

 water and evaporated at low temperature. Besides obtaining these crystals 

 from the blood of the stomach of the leech they also prepared them by 

 mixing 5 or 6 drops of the freshly drawn blood from the heart with one or 

 two drops of distilled water, and then sealing up the preparations with gold 

 size. They state, however, that exposure to the air favors the formation 

 of the crystals, which first form around and in the neighborhood of coagula. 

 In the case of one of the leeches, on exposing some of the blood on the fourth 

 day, they obtained blood which, when sealed up and allowed to stand, 

 developed beautiful colored crystals of exactly the same shape as those 

 which are colorless. The sole difference, they state, was in the color, and 

 they therefore were inclined to regard the latter as being closely related to 

 hemoglobin, if not identical with it. They did not find any crystals from 

 the blood of the newt that had been ejected by the leech. 



Studies were also made of the influences of certain reagents on the crys- 

 tallization of rat's blood. Stirling and Brito found that common salt and 

 urine prevented the diffusion of hemoglobin from the corpuscles, and there- 

 fore prevented crystallization; but a weak solution of pure urea behaved 

 exactly like water, liberating the hemoglobin and thus permitting of crys- 

 tallization. From this they conclude that the presence of common salt in 

 the urine is sufficient to neutralize the effect of the urea. The crystals 

 found in the solution were exactly the same as those formed after the 

 addition of water. Crystals appeared in a few minutes when chloroform 

 was freely mixed with a drop of rat's blood on a slide and covered and 

 examined in the usual way, but the ordinary flattened prisms with beveled 

 ends were shortened so as to be hexagonal. They also made the interesting 

 observation that the passage of a galvanic current causes a deposition of 

 crystals equally well at both negative and positive poles, but that the induced 

 current was without effect. 



The use of chinolin to increase crystallizability was reported by Otto 

 (Zeit. f. physiolog. Chemie, 1882, vn, 57). He employed an alcoholic solution 



