566 
POrCJLAB SCIENCE REVIEW. 
instance their presence was indicated, in the early stage of the experiments, 
by the formation of a film, which took place in some on the second, and in 
others not till the nineteenth day. The result of the thirty-seven experi- 
ments is, that the boiled solutions of organic matter made use of, exposed 
only to air which has passed through tubes heated to redness, or enclosed 
with air in hermetically sealed vessels, and exposed to boiling water, 
became the seat of infusorial life. 
The Microscope in Meteorology. — Mr. Sorby has turned the microscope 
upon meteorites, or rather upon sections of those exotic minerals, with a 
view to ascertain their origin by close examination of their microscopical 
structure. The evidence thus far appears to he strong in favour of the 
conclusion that they are formed by the aggregation of smaller fragments, 
or minute particles, in which particular they are most nearly resembled, 
among terrestrial rocks, by consolidated volcanic ashes. Is there anything 
in this fact of aggregation which touches the nebular hypothesis? 
Action of Magenta on Vegetable Tissues. — Mr. J. G. Lynde describes a 
series of experiments on cuttings of vallisneria immersed in a solution of 
that dye in glass cells. He finds that, so long as vital action continues, 
the cell walls and moving ehlorophyle retain their green colour, but the 
injured cells are immediately deeply reddened, and their contents gradu- 
ally acquire the same colour. Between the cell walls there exists an 
intercellular membrane of low vitality, which becomes rapidly coloured 
while the rotation is going on. He further observed what he believed to 
be traces of cilia, which, when rotation ceased, left irregular markings, 
either corrugated, or having raised excrescences, which had the appearance 
which would be produced by cilia falling against the cell wall in various 
positions upon the suspension of vital action. The ehlorophyle vessels 
appear to resist the action of the magenta for some time after rotation has 
ceased, indicating a vitality to a certain extent, at least, independent of 
that of the cell. 
New One-twentieth Objective. — Messrs. Smith & Beck have produced a 
new -A^th objective-glass, which is well spoken of. The definition is 
described as excellent, and the facility of working equal to that of a low 
power. The improvements which have recently taken place in optical 
instruments hai r e thus rendered the use of such a glass not only possible, 
but desirable, although but a few years back glasses of a much lower 
power were liable to very considerable working objections. In the present 
case, a large angle of aperture, combined with flatness of field and perfect 
correction, render the -^yth a lens which will do good service. 
New One-twenty-fifth Objective. — Messrs. Powell & Lealand have 
Succeeded in making a ^--inch object-glass, magnifying 7,500 diameters, 
and thus enlarging a given area fifty-six million times ; but we are unable 
at present to say anything concerning the working of this optical 
marvel. 
Cheap French Microscope. — M. Chevallier lias announced, through the 
Imperial Academy of Sciences, that he has constructed a compoflnd micro- 
scope of 250 magnifying power, which he can supply at the moderate sum 
of sixty to seventy francs (50s. to 60s.). 
