244 
Notes. 
[April, 
rule lines at a very minute but determinable distance ; strange 
to say the lines are not straight ones, but portions of a large arc ; 
the lines, however, not exceeding one-fiftieth of an inch in 
length, the curvature is not perceptible. The diamonds used for 
ruling are worked to knife-edges, in some instances ground, in 
others chipped, but made with such delicacy that microscopic 
examination fails to deteCt any serrations : in this and the glass 
employed would seem to lie the secret of the fine quality of line 
produced by M. Nobert. The note-book of the inventor accom- 
panies the machine, and in it the performance of each diamond 
has been recorded, and much useful information that will pro- 
bably enable the machine to be used. Experts who have 
examined the machine since it has been in England do not con- 
sider the mechanical contrivances the best that could have been 
devised; but the faCt nevertheless remains that Nobert contrived 
to execute rulings which have not been equalled. The resolution 
of the nineteenth band, in which the distance of the lines — ac- 
cording to the measurements of Dr. Pigott — is 112-595 to the 
inch, and formerly supposed to be impracticable, is now accom- 
plished without much difficulty. There is also an adaptation 
for ruling the longer and comparatively coarser lines for diffraction 
plates for spectroscopes. 
The death of Charles Vance Smith, of Carmarthen, is an- 
nounced. The deceased was noted for his skill in preparing 
vegetable tissues for the microscope : his series illustrating the 
manuals of Sach and Thome are well known, and are admirable 
reproductions of the figures in those works, and of immense 
value to students unable to procure the specimens for them- 
selves. 
M. Arnaud has proved that the orange-red colouring-matter of 
leaves (erythrophyll) is identical with carotine — the colour of the 
carrot. 
We are glad to find that the London SeCtion of the Society of 
Chemical Industry has completely condemned the New Rivers’ 
Pollution Bill. 
We learn that a new Poisons’ Bill has been introduced into 
the House of Lords. As any conceivable measure of this kind 
will press heavily both upon the industrial arts and upon scien- 
tific research, we recommend that it should be opposed in every 
possible manner. 
According to a well-informed French contemporary the excre- 
ments of dogs are now collected in Paris and worked up into 
peptones and powdered extracts of meat ! 
According to “ Reimann’s Faerber Zeitur.g ” a cat which had 
been accidentally imprisoned for six weeks, in the ruins of a 
