1883.] Scientific News. 229 
tained, they may be tabulated and kept for subsequent use. To 
ascertain these positions for any given magnification, a millimeter 
scale may be placed on the object-table, and the camera and ob- 
jective moved until the picture projected on the drawing plane 
has the desired enlargement. When the scale is replaced by the 
object, care must be taken to have the surface, which is to be out- 
lined, in the plane previously occupied by the scale. To this end 
it may be necessary to move the object-table a very little, in 
order to give a sharply defined picture, the positions of the cam- 
era and objective being left unaltered. 
The object-table measures 8 X 10°", and has a central perfora- 
tion 2.5 in diam. The whole apparatus is completed by a 
movable shade, designed to cut off the light falling on the lens 
and on the drawing plane. 
It is hardly necessary to remark that opaque objects require 
direct sunlight or light from a lamp supplied with a bull’s eye 
condenser. j 
This instrument, including lens, and Oberhauser’s camera 
lucida, may be obtained from Geo. A. Smith & Co., 7 Park street, 
Boston, for thirty dollars. For everything except the camera, 
the price is fifteen dollars. 
Tue Microse oF “ Rep Evit,” a Pic Disease.—A disease of 
Pigs, known in France as rouget or mal rouge (red evil), has of 
late, says the Anglish Mechanic, wrought terrible ravages in the 
hone valley, 20,000 pigs having succumbed in a year. M. Pas- 
teur has detected the microbe to which the disease is due. It is 
Something like that of chicken cholera, but much smaller and 
different in physiological properties. Its form is that of the figure 
8. It has no action on fowls, but rapidly kills rabbits and sheep. 
Injected in almost inappreciable quantity into pigs, it suffices to 
Cause mortal disease. M. Pasteur has succeeded in producing 
_ an attenuated form of this virus, wherewith healthy pigs may be 
. Vaccinated and rendered refractory to the contagion. 
At 
SCIENTIFIC NEWS. 
= „ — Dr. D. G. Brinton, of Philadelphia, is about to publish an 
‘Important work entitled LIBRARY OF ABORIGINAL AMERICAN LiT- 
ERATURE, The following are some of the works which it is pro- 
_ posed to issue in this series: No. 1. THE CHRONICLES OF THE 
Mayas, edited by D. G. Brinton, M.D. This volume will contain 
Se brief chronicles in the Maya language of Yucatan, written 
shortly after the conquest, and carrying the history of that ang 
ple ack many centuries. Four of these have never been put 
k hed, nor even translated into any European tongue., Each will 
RAT in the original, with a literal translation and grammati- 
and historical notes. To these will be added a history of the | 
H 
