. these are carefully cleansed in ether and alcohol so that fat, fiber and all parti- cles of dust are removed. [Water is sufficient for cleansing cover-glasses pro- vided they are properly polished with silk or tissue paper afterwards.—Ed.] On a cover-glass of this kind a small drop of blood which has exuded from a prick of the finger is collected; this glass is dropped, blood side downward, upon a second glass, with the result that the blood soon spreads out spon- taneously in a thin film between the two very flexible glasses to about three- quarters of their extent, as if in a capillary spa
. these are carefully cleansed in ether and alcohol so that fat, fiber and all parti- cles of dust are removed. [Water is sufficient for cleansing cover-glasses pro- vided they are properly polished with silk or tissue paper afterwards.—Ed.] On a cover-glass of this kind a small drop of blood which has exuded from a prick of the finger is collected; this glass is dropped, blood side downward, upon a second glass, with the result that the blood soon spreads out spon- taneously in a thin film between the two very flexible glasses to about three- quarters of their extent, as if in a capillary space. After a complete distribu- tion of the drop of blood, the glasses are removed from one another [by sliding off the upper of the two covers without any lifting or tilting, but strictly in the plane of their surfaces.—Ed.], and the blood is seen distributed upon each in a uniform layer. If the drop taken was small enough, the blood cells are found in an even layer side by side without over- lapping each other. In view of the fact that the red blood-corpuscles are dam- aged with extraordinary ease, especially by moisture, this maneuver should not be at- tempted with the unaided hand; for the moisture of the tip of the fingers is capable of changing the outlines of the red blood-corpuscles and of extracting their hemoglobin. For this reason, in the preparation of these specimens two forceps should be used in the manner depicted in Fig. 18. [For any one whose fingers are not habitually and obviously damp the use of forceps is unnecessary. -Ed.] When the blood films have dried. which usually happens within twenty to thiily seconds, it is necessary before subjecting them to the stain to fix the blood in a suitable manner. For practi- cal purposes it is sufficient usually if the specimens are placed for five minutes in a solution of formol in 100 parts of absolute alcohol. After this method of fixation almost all the stains which need practically be considered may be em- pl
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectblood, booksubjectpoi
