A 



-: 



526 BLOOD-COAGULA AND CRYSTALS. [SECT. 221. 



4, caudate cells, pale or with pigment (Virchow, Arch, ii.) ; 5, pale, finely 

 granular, roundish heaps, found by Funke in the blood of the splenic vein, 

 and by myself in the blood of the spleen and liver in sucking animals. In 

 the latter case they are little masses o - oi'"to o"oa'" in size, with an ill-defined 

 outline, and with nuclei which swell up in water to o - ooo5'" or o - ooo8'". These 

 dissolve rapidly in alkalies, and after a while in acetic acid ; but they are not at- 

 tacked by ether and alcohol and probably consist, therefore, of particles of easily 

 Fig. 214. soluble albumen. — We have still 



to mention here the elementary 

 forms arising external to the body, 

 or on stagnation of the circulation, 

 the fibrinous coaffvla and red crys- 

 tals. The former, as they appear in 

 blood-coagula, mostly have the form 

 3/ of fine fibrils extremely densely 



matted together in an irregular 

 manner, with here and there some 

 4'f! ""' ; thicker and straighter fibres, which 



measure uniformly o'ooi'" to o - oo2'" 

 . .. „. ., . . ., , n . .. in breadth. These fibrinous ele- 



Crvstals obtained from fresh blood. 1. prismatic . . 

 crystals from man : 2. tetrahedra from the porpoise ; ments are also said to occur in the 

 3. six-sided plate from the squirrel. After Funke. n r 1 1 it ~ ;a~„ 



* form of plates resembling epider- 



mis-scales (fibrine flakes, Nasse). — The red crystals which form from the 

 blood, have of late years received increasing attention. They are of two kinds, 

 the one occurring in normal fresh blood, spontaneously or on mere desicca- 

 tion ; the other kind being met with in old effusions of blood, in decomposed 

 specimens, or in blood subjected to certain chemical agencies. Crystals 

 ranged under the latter head maybe divided into three sorts: 1, the so- 

 called hcematoidin crystals, described by Virchow in old extravasations, which 

 have the form of rhombic plates, characterised by' their insolubility in water, 

 alcohol, ether, or acetic acid, and also by their giving with strong sulphuric 

 acid, a play of colours similar to that produced by nitric acid on the colouring 

 matter of the bile ; 2, certain crystals observed by Leydig (Zeitschr. J. wiss. 

 Zool., 1, p. 266), and Berlin, in specimens of decomposed blood from the 

 stomach of the clepsine, and of a kind of mite called amblyomma exornatum ; 

 3, red, brown, or even black crystals, produced by Teichmann in blood, by the 

 agency of acetic acid ; considered by their observer to be pure hajmatin, and 

 named accordingly, hcemin- crystals (Zeitschr. f. rat. Med.,Hd. iii., 1853, p. 375 ; 

 and viii. p. 141). The interest of these last crystals has recently been greatly 

 enhanced, from their having been used by Brilclte in the diagnosis of blood- 

 spots. A blood-stain is treated with distilled water, and the solution, with a 

 little common salt, is evaporated in vacuo over sulphuric acid, then wetted 

 with glacial acetic acid and evaporated on the water-bath. A few drops of 

 distilled water being added to the product, TeichmanrCs crystals may be 

 examined. — The other class of red crystals, those which are found in normal 

 blood, perfectly fresh, were described by myself in the year 1849 (Todd's 

 Cyclop. ofAnat. , June, 1 849, Art. Spleen, p. 792 ; Zeitschr. f. w. Zool. i., p. 266 ; 

 and Micr. Anat. ii., p. 280). I found them in the blood of the dog, of fishes, 

 and of a python ; sometimes within the red blood-corpuscles, sometimes free 

 in the blood, especially of the spleen and liver. From their occurrence in the 



