STAINS FOB BLOOD. 349 



riment for each form. As a rule, it should be strong, 1 to 

 2 per cent. According to Biondi, 2 per cent, is best. Fixed 

 specimens may be preserved for use in acetate of potash 

 solution (MAX FLESCH, Zeit. f, wiss f Nik*, v, 1, 1888, p. 83). 

 The time-honoured .process of drying drops of blood over a 

 flame gives rise to. great deformation of the elements, and 

 should be abandoned. 



693. Stains for Blood. Blood prepared as above can be 

 satisfactorily stained with many of the usual reagents, such 

 as picro-carmine or haeinatoxylin. 



Eosin stains rose-red all parts of blood-corpuscles that 

 contain haemoglobin (see WISSOWSKY, Arch. /. mik. Anat. } 

 1876, p. 479) ; parts that do not contain haemoglobin, such as 

 the nucleus, remaining unstained. This suggests double- 

 staining with eosin and haeruatoxylin. 



WISSOWSKY (1. c.) stains in a solution of equal parts of 

 eosin and alum in 200 parts of alcohol, and then with hsema- 

 toxylin. 



MOORE (The Microscope, 1882, p. 73 ; Journ. Roy. Mic. Soc., 

 1882, p. 714) stains for three minutes in a similar solution 

 without the alum, washes, and stains for two minutes in a 

 1 per cent, aqueous solution of methyl-green. Red corpuscles, 

 red; nuclei and white corpuscles, bluish-green. 



MERKEL'S carmine and indigo-carmine stain has been dis- 

 cussed above, 230 and 691. 



HARRIS (Journ. Poy. Mic. Soc., 1885, p. 537) recommends 

 " Spiller's purple " in 1 per cent, solution. 



Fresh, (unfixed) blood is perhaps best treated as follows 

 (BizzozEito and TORRE, Archivio per le Scienze mediche, vol. iv, 

 No. 18, 1880, p. 390) : Dilute a drop of blood with 0'75 per 

 -cent, salt solution in which has been dissolved a little methyl- 

 riolet. This liquid in no wise affects the form of the elements, 

 stains intensely the nucleus of the red corpuscles, and, in the 

 white, stains the nucleus intensely, and the protoplasm less 

 intensely. May be used for the study of bone-marrow and 

 spleen. 



For the staining of the blood-plates of BIZZOZERO, this 

 observer (Arch. /. path. Anat. u. Phys. ; Zeit. /. wiss. Mik., 

 1884, p. 389) employs a 0'02 per cent, solution of methyl- 

 violet in salt solution, or a 1 : 3000 solution of gentian- violet. 



