344 Chronicles of Science. | April, 
the actual yield per acre, causes it to grow of a much better quality. 
There is no doubt that what is here shown to be the case with grass 
holds good equally with cereal and other crops. 
A lifetime might be spent in investigating the mysteries hidden in 
a bee-hive, and still half of the secrets would be undiscovered. The 
formation of the cell has long been a celebrated problem for the 
mathematician, whilst the changes which the honey undergoes offers 
at least an equal interest to the chemist. Everyone knows what honey 
is like when fresh from the comb. It is a clear yellow syrup, without 
a trace of solid sugar in it. Upon standing, however, it gradually 
assumes a crystalline appearance—it candies, as the saying is—and 
ultimately becomes a solid mass of sugar. * 
It has not been suspected that this change was due to a photographie 
action—that the same agent which alters the molecular arrangement 
of the iodide of silver on the excited collodion plate, and determines 
the formations of camphor and iodine crystals in a bottle, also causes 
the syrupy honey to assume a crystalline form. This, however, is the 
case. M. Scheibler* has enclosed honey in stoppered flasks, some of 
which he has kept in perfect darkness, whilst others have been exposed 
to the light. The invariable result has been that the sunned portion 
rapidly crystallizes, whilst that kept in the dark has remained perfectly 
liquid. We now see why bees are so careful to work in perfect dark- 
ness, and why they are so careful to obscure the glass windows which 
are sometimes placed in their hives. The existence of their young 
depends on the liquidity of the saccharine food presented to them, and 
if light were allowed access to this the syrup would gradually acquire a 
more or less solid consistency ; it would seal up the cells, and in all 
probability prove fatal to the inmates of the hive. 
The Magnesium Light is gradually attracting more and more at- 
tention, as there appears to be a probability of the metal being ob- 
tained at a reasonable price. Ata recent meeting of the Manchester 
Literary and Philosophical Society, Professor Roscoe exhibited the 
light emitted by burning a portion of a fine specimen of pure mag- 
nesium wire, one inch in diameter. In a memoir on the subject by 
Professors Bunsen and Roscoe, they show that a burning magnesium 
wire 0°279 inch thick evolves as much light as 74 stearine candles, 
5 to the pound, In one minute about -12 grammes of magnesium 
would be burnt, and in 10 hours about 72 grammes or a little over 2 
ounces. In order to produce the same light with the candles for 10 
hours, there would have to be burnt about 20 lb. of stearine, so that could 
magnesium wire be produced at a few shillings per ounce our houses 
might at once be illuminated by this easily managed and intensely 
powerful light. 
A good photometric process, easy of application, and tolerably ac- 
curate in its results, is, and perhaps will long remain, a desideratum. 
One of the best which has come under our notice has just been devised 
by M. Z. Roussin ; he dissolves equal parts of dry perchloride of iron 
* «Journ. de Pharm. et de Chimie,’ 1863. 
