1877.] Microscopy. 189 
a power of 1800, was determined by comparison with a standard of 
known accuracy. Only the circular disks were measured, in the thinnest 
part of the film, where they were least distorted in drying and most 
nearly in a natural condition, this method being believed to give the 
dimensions of the normal cell-elements more satisfactorily than can be 
accomplished by taking the average of the different diameters of the dis- 
torted corpuscles. So slight a deviation from a circular form as an oval 
having diameters of 1-3030 and 1-2857 was easily recognized, and such 
individuals were discarded, but all isolated circular red disks which ap- 
peared in the field were measured without selection. The measurements 
were recorded in fractions of an inch. Of 1400 corpuscles examined, 
six had a measurement of 1—4000, ten a measurement of 1-2777, and 
the remainder were between these two extremes. EKighty-three per cent 
of the whole measured from 1-8448 to 1-3030, and consequently ap- 
peared of about the same size under a power of 200. The slightly 
smaller averages of the Italian, Swedish, and Norwegian specimens are 
believed to be too small for a decisive indication of a natural difference, 
and the general result is believed by the author to indicate the essential 
identity of the different specimens studied. We have prepared the fol- 
lowing table, which embodies all the data published in Dr. Richardson’s 
paper in the American Journal of Medical Science for January, 1877 : — 
; & a alg 
n K] - 3 i 
oe ee 2 FE | 
S 5 f keL LA 2/86 
AP ee ie 
E = S ‘ ge) es ag 
g © H 38 ES 55 
NATIONALITY OF SuBszcr. : E E 3 4 Ee 53 [5] p 
3| 8 È El á |$8|$3]58 
2 pe = a f 8128 Ş 
5 © A S g om fe Fi T 
mM be o fz] 3 
s| 3 > E a |$8/| 98/82 
© £ gr] æ i 3 
a| B £ Éj 5 a} 5n| 5s 
Ji z 4 =] H le a 
ee .. | 100 | 1-3212 | 1-2777 | 1-3737 | 8 | 82 |10 
DOME Sd, x5. SONI 80| 100 | 1-5226 | 1-2777 | 1-3571 | 6| 89| 5 
Belgian E AR wate wx Wali hiurs 38 | 100 | 1-3 1-2777 | 1-3846 | 7} 88] 5 
«SRA N 40 | 100 | 1-3203 | 1-2857 | 1-4000 | 7 | 82} 11 
eb eo) 5280.) ecole 29 | 100 | 1-3197 | 1-2777 | 1-3846 | 4 | 80} 16 
ENE ROR TE » | 25 | 100} 1-3257 | 1-2857 12} 82) 6 
a 27 | 100 | 1-3190 | 1-2857 | 1-3571 | 2| 91} 7 
Norwegian............... 35 | 100 | 1-3252 | 1-2857 | 1-4 86] 4 
a SE Sa 33 | 100 | 1-3254 | 1-2777 | 1-3737 | 13 5 
ee 35 | 100 | 1-3272 | 1-2777 10 7 
agree Oe aE ee 67 | 100 | 1-32 2777 | 1-3737 | 12 | 80 | 8 
we mulatto, boris id U.S. | 52 | 100 | 1-3229 | 1-2857 | 1-3856 | 11 | 83 6 
rokee Indian, born in S 
a oe 48 | 100 | 1-3215 | 1-2857 | 1-4000 | 10 | 8 | 7 
nglish we born in 
Wad E ok ce 40 | 100 | 1-3191 | 1-2777 | 1-3846 | 6| 85 | 9 
ee .. | 1400 | 1-3224 | 1-2777 | 1-4000 | 8| 83/| 9 
eee ST" 
