ILfiMATOIDINE. 175 



We have already become acquainted with three different 

 kinds of crystals, of which haematine seems to be the 

 common origin. 



To the first form, with which I at one time busied 

 myself much, I have given the name of Hcematoidine. 

 This is one of the most frequent of metamorphic products, 

 and is spontaneously formed in the body out of haema- 

 tine, and that indeed often in such large quantities that 

 its excretion can be perceived with the naked eye. This 

 substance in its perfect form presents itself in the shape 

 of oblique rhombic columns, and is of a beatiful yellow- 

 ish-red, or frequently, when in thicker pieces, deep ruby- 

 red, colour, and forms one of the most beauti- 



Fio. 58. 



ful crystals we are acquainted with. In little _-, 



plates too it is not uncommonly met with, and 

 frequently bears a considerable resemblance 

 to the crystalline forms of uric acid. In the 

 majority of cases the crystals are very small, 

 not merely microscopical, but even somewhat difficult of 

 observation with the microscope. A man must either be 

 a very keen observer, or provided with special prepara- 

 tory knowledge, else he will frequently discover in the 

 spots where the haematoidine is lying nothing more 

 than little streaks, or an apparently shapeless mass. 

 But, upon more accurate inspection, the streaks resolve 

 themselves into minute rhombic columns, the mass into 

 an aggregation of crystals. This substance may be con- 

 sidered as the regular, typical, ultimate form into which 

 haematine is converted in any part of the body where 

 large masses of blood continue to lie for any length of 

 time. An apoplectic effusion in the brain, for example, 

 cannot be repaired by any other process than by a large 

 portion of the blood undergoing this form of crystalliza- 



Fig. 53. Crystals of Hromatoidine in different forms (Comp. ' Archiv. f. path. 

 Anat.,' vol. i, p. 391, plate iii, fig. 11). Magnified 800 diameters. 



