SOME OTHER HISTOLOGICAL METHODS. 447 



Blood. 



806. Introduction. The technique of blood is most elabo- 

 rate ; see, for instance, the voluminous work of HAY EM, Da 

 sang et de ses alterations anafomiques, pp. 1035, with 126 

 figures, Paris, Masson, 1889 (a report of ove'r twenty pages 

 on this important work is contained in Zeit. f. wisx. Mik., 

 vi, 3, 1889, p. 330, et seq.) COLES, The Blood : how to 

 examine and diagnose its diseases, London, Churchill, 1898, 

 260 pp., and 6 pis. ; as well as the numerous memoirs of 

 LOWIT, EHKLICH, and others (see the bibliography in GIGLIO- 

 Tos, Mem. Accad. Torino, xlvii, 1897, p. 37 ; also previou* 

 editions) . 



I confine myself to giving a few methods that may be 

 useful to the general student. 



807. Fixing and Preserving Methods. The school of Ehrlich 

 fix by heat. A film of blood is spread on a cover-glass and 

 allowed to dry in the air, and then fixed by passing the 

 cover a few times, three to ten or twenty, through a flame, 

 or by laying it face downwards on a hot plate kept for 

 several minutes or as much as two hours at a temperature 

 at which water not only boils but assumes the spheroidal 

 state (110 to 150 C.). For details see GULLAND, Scottish 

 Med. Journ., April, 1899, p. 312 ; KUBINSTKIN, Zp.it. f. wiss. 

 Mik., xiv, 1898, p. 456 ; ZIELINA, ibid., p. 463 ; Journ. Roy. 

 Mic. Soc., 1898, pp. 488, 489. The method is, in my 

 opinion, unutterably barbarous, and should be abandoned in 

 favour of wet methods. 



In wet methods, either the blood is mixed at once, on 

 being drawn, with some fixing and preserving medium, and 

 studied as a fluid mount ; or cover-glass films are prepared 

 and put into a fixing liquid before the film has had time to 

 dry. 



MUIR (Journ. of Anat. and. Phys., xxvi, 1892, quoted from 

 Gulland, below) makes cover- glass films and drops them 

 into saturated sublimate solution, and after half an hour 

 washes, dehydrates, and passes through xylol into balsam. 



GULLAND (Brit. Med. Journ., March 13th, 1897; Scottish 

 Med. Journ., April, 1899) makes cover-glass films, and after 



