92 PROGRESS OF MICROSCOPICAL SCIENCE. 



wliicli is experienced in determining the kind of blood, by the ordinary 

 methods of examination in medico-legal cases. 



If examined with the microscope, as it is ordinarily found in the 

 dried state, the corpuscles are shrivelled and deformed. The addition 

 of water extracts the colouring matter, and though it causes them to 

 swell up, does not restore them to their original condition. It cau.res 

 the red corpuscles to lose their bi-coucave shape and approach the 

 spherical. The oval disks of reptiles, birds, &c., lose something of 

 their peculiar shape, and become more like mammalian blood. 



In moistening such blood he uses a solution of sulphate of soda, 

 or, bettor still, slightly acidulated pure glycerine. This preparation 

 " is carefully irrigated with a properly prepared alcoholic solution of 

 guaiacum resin: then, when a very small quantity of the ethereal 

 solution of the peroxide of hydrogen (ozonic ether) is introduced 

 beneath the glass cover," the red corpuscles are changed to an uniform 

 colour, which varies in the different corpuscles, " from a light sapphire 

 to a deep indigo blue." 



In the nucleated corpuscles of birds, reptiles, &c., however, " the 

 nucleus is seen as a sliarphj -defined, dark blue body, while the jjrotoplasm 

 surrounding it assumes a more delicate violet hue." The distinction 

 between the two kinds of blood, by this means, is so plain as to be 

 evident even to an ordinary gentleman of the jury. 



WJiat Pus is not. — The following interesting paper is contributed 

 to the ' Medical Examiner ' (Chicago, U.S.A.) for April, by Dr. Lester 

 Curtis, M.D. :— 



" A few years ago Conheim published some observations on the 

 white blood corpuscle, which confirmed the older observations of 

 Waller and Beale, and called attention to them ; for previous to this 

 time they had attracted little notice, especially on the continent of 

 Europe. These observations showed that, in inflammation, many of 

 the white blood corpuscles pass through the walls of the capillaries, 

 and appear outside of them. The corpuscles outside the vessels 

 continue their amoebiform movements, and possessing the power of 

 locomotion, were called ' wandering cells.' (?) 



" At the time of these observations it was well known that the 

 fresh pus corpuscle also had an amoebiform movement similar to 

 that of the white blood corpuscle. Pus occurs as the result of inflam- 

 mation ; and where there is inflammation there are large numbers of 

 wandering cells. Conheim concluded, therefore, that pus corpuscles 

 came from the wandering cells, and, as the wandering cells came from 

 the white blood corpuscles, therefore that a pus corpuscle was a white 

 blood corpuscle. He rejected as erroneous the previous opinion that 

 pus could be derived from any other source than the white blood 

 corpuscles. 



" Conheim's conclusion, that the pus corpuscle and the white blood 

 corpuscle are identical, has been widely accepted. It is due partly to 

 the acceptation of this theory that the name ' leucocyte ' has arisen — a 

 name which is aj)plied indiscriminately to the white blood corpuscle, 

 the lymph corpuscle, the wandering cell, and the pus corpuscle. 

 Some, in publishing their acceptation of the theory, have added the 



