one place is midnight at the other, the longest day corresponds to the
shortest, and mid-winter is contemporaneous with midsummer. In the
calculation of days and nights, midnight on the one side may be regarded
as corresponding to the noon either of the _previous_ or of the
_following_ day. If a voyager sail eastward, and thus anticipate the
sun, his dating will be twelve hours in advance, while the reckoning of
another who has been sailing westward will be as much in arrear. There
will thus be a difference of twenty-four hours between the two when they
meet. To avoid the confusion of dates which would thus arise, it is
necessary to determine a meridian at which dates should be brought into
agreement, i.e. a line the crossing of which would involve the changing
of the name of the day either forwards, when proceeding westwards, or
backwards, when proceeding eastwards. Mariners have generally adopted
the meridian 180 deg. from Greenwich, situated in the Pacific Ocean, as
a convenient line for co-ordinating dates. The so-called "International
Date Line," which is, however, practically only due to American
initiative, is designed to remove certain objections to the meridian of
180 deg. W., the most important of which is that groups of islands lying
about this meridian differ in date by a day although only a few miles
apart. Several forms have been suggested; these generally agree in
retaining the meridian of 180 deg. in the mid Pacific, with a bend in
the north in order to make the Aleutian Islands and Alaska of the same
time as America, and also in the south so as to bring certain of the
South Sea islands into line with Australia and New Zealand.

ANTIPYRINE (phenyldimethyl pyrazolone) (C11H12N2O), is prepared by the
condensation of phenylhydrazine with aceto-acetic ester, the resulting
phenyl methyl pyrazolone being heated with methyl iodide and methyl
alcohol to 100-110 deg. C.:

CH3.C=N \ CH3.C-N.CH3
>N.C6H5 -> || >N.C6H5
CH2-CO / HC-CO
Phenyl methyl pyrazolone Antipyrine

On the large scale phenylhydrazine is dissolved in dilute sulphuric
acid, the solution warmed to about 40 deg. C. and the aceto-acetic ester
added. When the reaction is complete the acid is neutralized with soda,
and the phenyl methyl pyrazolone extracted with ether and distilled _in
vacuo_. The portion distilling at about 200 deg. C. is then methylated
by means