134 On the Value of High Powers 



Further, in reg;ird to the red blood-disks of animals with 

 rounded corpuscles, I can perhaps best illustrate the principles that 

 guide us in their discrimination by suggesting that these bodies 

 may be aptly compared to different sizes of shot. Thus, for 

 instance, the red globules of man's blood are nearly twice the size 

 of the sheep's, and about four times that of the musk deer's, just as 

 No. 1 shot is perhaps double the magnitude of No. 5 and quadruple 

 that of No. 8. 



It is obvious, too, that a shot dealer in the latter case, or a 

 skilful microscopist in the former, would more quickly and surely 

 distinguish two analogous sizes of red blood, or of leaden globules, 

 from each other, than could an inexperienced apprentice in either 

 occupation. 



Hence it follows, that whilst we might be in doubt whether the 

 shot dissected out of the body of a wounded man was a No. 1 or a 

 No. 2, we could have no hesitation, after measuring it with a gauge, 

 in declaring it was too large for a No. 5 and a fortiori for a No. 8, 

 precisely as the corpuscles of man's blood might be confounded with 

 those of a monkey's, but on measurement are seen at once to be too 

 large for those of an ox or sheep. Nor can it be disputed that 

 mere measurement in either instance, when practically correct, is 

 quite sufficient to decide a doubtful case, as, for example, if I 

 was to shoot myself in the hand, and tlien assert that it had been 

 done by some one else, whose gun was known to be loaded with 

 No. 8 shot, whilst the grains in my flesh were actually of the size 

 of No. 1. 



It must be remembered, too, that whilst the relative differences 

 between corpuscles of human, ox, and sheep's blood remain the 

 same, the absolute difference becomes more perceptible in proportion 

 as the disks are magnified above, for example, those represented in 

 Dr. Taylor's work, so that when the former corpuscles appear f of 

 an inch and the latter f of an inch across (as they do under 

 the 3^(7), they can hardly be mistaken for another, any more than a 

 12-inch shell could be mistaken for a 6-inch shell, even by a 

 careless person, who would call a No. 1 a No. 5 shot. 



Ordinarily in criminal cases the microscopist is called upon to 

 determine, not whether a particular specimen is human, as distin- 

 guished from all other kinds of bloofl, but to discriminate simply 

 between the blood-corpuscles of a man and an ox, a man and a 

 horse, or a man and a sheep, and so establish or disprove the 

 defendant's story as to how his clothing or other articles became 

 stained with blood. Sometimes the much easier task is imposed 

 (as in a recent case wherein I was engaged) of diagnosing between 

 the blood of a human being and that of a bird.* In this instance 



♦ Trial of Charles Larribee for tlie murder of Lewis Williams, at Fianklin, 

 Venango Co., Pa., see ' Oil City Daily Derrick,' May 1st, 1874. 



