292 BLOOD AND BLOOD EXAMINATION 



with very little practice it protects us more fully from error thaji an investi- 

 gation of the fresh blood. 



The withdrawal of blood had best be made in the afebrile period; and 

 even here it must be borne in mind that, for as long a time as possible prior 

 to this, no quinin should be administered. 



Fixing the preparation is best accomplished by the use of absolute alcohol 

 for five minutes. [It seems likely that all the fixing methods described in 

 this article will soon be replaced by the fixation produced by methylic alcohol 

 which is the menstruum in which the various " Romanowsky " stains are dis- 

 solved. Using Leishman's or Wright's modification of the Eomanowsky 

 method we fix the specimen in the same fluid which later (when water has been 

 added) stains the specimen. This saves much time, trouble, the apparatus 

 and expense. The technic is given in d,etail below. — Ed.] Staining is best 

 done either by a one per cent, methylene-blue solution, or by the Chenzinsky 

 methylene-blue eosin mixture mentioned in another place, or after the method 

 especially proposed for the study of malaria by Eomanowsky-Ziemann. 



With an enlargement of about 500 and the use of an oil immersion, it is 

 not difficult even for the novice to recognize the fully developed plasmodium 

 within the red blood-corpuscles. First, the blue tint which they acquire from 

 the methylene-blue readily distinguishes them from the nucleus of the cell; 

 this is an uncommonly delicate sky-blue in contrast with the darker blue of 

 the nucleus, which more closely resembles the actual color of the material used 

 in staining. [With the Eomanowsky stain which is now widely used in this 

 country for all blood-specimens, the nucleus is colored crimson and its con- 

 trast both with the blue of the parasite and the yellow of the surrounding 

 corpuscle forms thus one of the most recognizable features of the organism. 

 ■ — Ed.] By the amount of pigment the recognition of the plasmodium is 

 also decidedly facilitated. 



It is more difficult if only the very young forms of the plasmodia are 

 present, those which are still very small, and have not as yet formed pigment. 

 Occasionally the characteristic seal-ring shape facilitates their recognition; 

 frequently, however, the apparently structureless forms may be confused with 

 the nuclei or the fragments of a nucleus of the erythrocytes, or with the dots 

 of " stippled " erythrocytes. Here the character of the staining in particular 

 gives a point of support for their recognition. Observations made at a more 

 favorable time, and eventually an examination of the fresh blood to determine 

 the motility of these bodies, furnish convincing proof. 



How important it is to carry out an examination for plasmodia is shown 

 by the fact that, according to Eobert Koch, the prophylaxis as well as the 

 therapy of malaria is intimately connected with the results of the blood 

 findings. 



The investigation itself, however, is so simple that it should never be 

 omitted in any case in which long protracted, perplexing fever is present, or 

 in which the history, or the condition of the spleen, or other clinical phenom- 

 ena point to the possibility of a malarial infection. Especially in regions 

 in which malaria is quite rare valuable time for the patient is frequently lost, 

 because the physician has neglected the examination of the blood, supposing 



