THE MICROSCOPE. 93 



Microscopical Examination of Blood in the Diagnosis 

 OF Disease. — For the purpose of these investigations, M. Hayem 

 recommends the use of a cell thus constructed: a thick plane glass 

 slide has a disk made on it of about 4 mm. in diameter; the rest of 

 the slide is silvered; a small drop of blood is placed on the disk and 

 is covered by a thin cover-glass, so that a layer of uniform thickness 

 is obtained. A little saliva placed round the edge will prevent any 

 evaporation. 



When blood is treated with a mixture of 200 grammes of distilled 

 water, one gramme of pure chloride of sodium, five grammes of 

 sulphate of sodium, and half a gramme of pure bichloride of mercury, 

 the blood-corpuscles are separately isolated and distinguished from 

 the other constituents. The fibrine then breaks up into two distinct 

 groups. 



Perfectly normal blood, thus treated, shows the following reac- 

 tions. At the moment when it coagulates it is traversed by a very 

 delicate network of filaments. If at the moment of coagulation a 

 reticulum of thick fibrillce is seen, we may be sure that we have in- 

 dications of an inflammatory lesion, and the modifications in the 

 processes of coagulation are due to the extent and intensity of the 

 inflammation. Pyrexia is not accompanied by any appreciable 

 modification of the fibrine; but when fevers are complicated by in- 

 flammatory process there are such modifications. In small pox they 

 only appear with the suppurating fever; in scarlet-fever and scarla- 

 tina the fibrine only augments at the period of desquamation. So 

 again, in typhoid and intermittent fevers the so-called phlegmatic 

 characters only appear when the disease is complicated by inflam- 

 mation. 



When cachectic conditions are not the results of chronic dis- 

 eases, which bring about inflammatory lesions, the reticulum of the 

 pure blood generally remains invisible, or is obscure, notwithstand- 

 ing the unusual abundance of hoematoblasts. Examination by the 

 aid of the solution already described, shows, however, that the 

 fibrine is allied; in advanced cases one often observes the so-called 

 "plaques cachectiques," due to the infiltration of the haematoblasts 

 by a finely granular substance, which points to a qualitative change 

 in the characters of the fibrine. — Royal Microscopical Journal. 



