NOTES. 817 
The elimination of every, even the slightest, chromatic aberra- 
tion obtained by this means increases, in my opinion, the defining 
and penetrating power of the microscope, and enlarges its domin- 
ion on the field of observation. Different other means have been 
now and then suggested, such as an alcohol light saturated with 
chlorine of iodine, or a light passed through a stratum of cupreo- 
ammoniacal solution, or even through a glass of cobalt; all these 
lights may be very useful and for some special purpose even pref- 
erable to any other, as Dr. Woodward observed, speaking of pho- 
tography; but for direct observations with the microscope, the 
effects obtained by them are by no means to be compared with 
the marvellous results of a mono-chromatic illumination. And I 
do not think it absolutely necessary for this purpose to have 
recourse to a beam of the swn,.which in many countries less fa- 
vored than Italy is not rarely a mere desideratum, and very often a 
dim, cloudy thing. A brilliant luminous point of electric light — 
a light obtained from oxhydrogenic flame — acting upon lime, 
magnesium, or zirconium, perhaps also the magnesium-wire lamp, 
may supply the deficiency of the sunbeam. Each of these simply 
white lights decomposed through a prism, will give a mono-chro- 
matic illumination sufficient to reveal the best structural details, 
which up to this day have baffled the keenest researches of the 
student.— Count Casrracane, Monthly Microscopical Journal. 
ANTHROPOLOGY. 
Supposep Inpran Corn Huskers.—In the museum of the 
Smithsonian Institution are several Indian stone implements like 
that noticed on p. 16 of the present volume of this journal, which 
are said to bear a striking resemblance to iron corn huskers now in 
use in the West. —Eps. 
NOTES. 
At the Manchester Literary and Philosophical Society, Mr. 
Boyd Dawkins exhibited a number of casts in plaster of Paris of 
various objects of natural history, and explained the process by 
which any one can make them for himself. The material of the 
