H^EMATO-CRYSTALLINE. 



smallness of the quantity, we are still able to obtain 

 hsemine. When the mass of blood is so very small, the size 

 of the crystals is certainly also extremely minute, and we 

 then find, as in the case of haematoidine, small needles of 

 an intensely brown colour and provided with acute angles. 

 The third substance which belongs to this series, is the 

 so-called Hcemato-crystalline, a substance about the dis- 

 covery of which the learned still dispute, for the simple 

 reason that it was found out piecemeal. The first obser- 

 vation concerning it was made by Reichert in extrava- 

 sations in the uterus of the guinea-pig, in a preparation 

 which, I think, had already lain for some little time in 

 spirits. This observation of his acquired especial signifi- 

 cance because he showed that these crystals in certain 

 respects behaved like organic substances, inasmuch as 

 they became larger through the action of certain agencies, 

 and smaller through that of others, without any change 

 of form, a phenomenon which, up to that time, had not 

 been known to take place in crystals. Afterwards these 

 crystals were again discovered by Kolliker, but Funke, 

 Kunde, and especially Lehmann, have examined them 

 more closely. The result has been that they are very 

 different in different classes of animals, but hitherto it has 

 not been possible to discover any definite reason for their 

 existence, or to obtain any insight into the nature of the 

 substance itself. In man the crystals are tolerably large. 

 At first it was believed that they only occurred in the 

 blood of certain organs, but it has since turned out that 

 they occur everywhere, though they are obtained with 

 greater readiness in certain morbid conditions. In a few 

 very rare cases it happens that they are found already 

 formed in the blood of the dead bodies of animals. These 

 crystals are very easily destructible ; both when they dry. 

 up and when they become moist, or are brought into 

 contact with any fluid medium, they perish, and they are 



