The St. Louis Republic. [volume] (St. Louis, Mo.) 1888-1919, 1903-08-31

necessary is to transfer this invisible pic
ture to an ordinary piece of gelatine paper,
for then. after contact of thirty seconds,
it can be developed in several ways. as, for
example. by transferring it to a solution of
iron sulphate
The result in this case will be an oxida-
! ton of the Iron sulphate on all those places
9ns has
solution of gallic acid is now applied the
result ...l, will be a genuine ink picture.
those now in use ss F a n mo- light Of any any
| kind is needed: for picture can be printed
! Just as well in darkness as in daylight.
ing sensitive to light. will keep for an in
! definite time. unlike the ordinary sensitive
papers. which are good for only brief
| days. Third. with the very cheapest ma
teria!s variety of colors can be obtained.
for there is no limit in this respect, almost
ing at our disposal. Fourth. this method Is
| much cheaper than any other. Fifth. being
wholly mechanical. it enables one to print
large editions In very short time.
Any design or drawing can be quickly
copied by this process and how important
is craftsmen as well as publishers Of
stand Finally. it should be remembered
that the silver used in the process does not
take any part in the reaction. and. there
fore. can be used for any number of
prints"
PRODUCING NITRATES.
Doctor Heimrod also spoke in glowing
terms of Professor Oswalds novel method
Of producing nitric acid from ammonia.
This. also, catylitic process he
said. land is cheap. Professor Oswald al
lows air to go through the ammonia and
this mixture of ammonia and air is then
passed over heated platinum, the result be-
| ing that the oxygen of the air oxidizes the
1nyio nit ocSl ifrin mir no
produced in this way much cheaper than It
can be obtained at present. To Germany. n
discovery of this kind is naturally of vas.
| Importance, for it is an agricultural country
and uses much artificial manure rich in nj
trates. Yet, for its nitrates it has hitherto
been dependent on Chile. and 1t has been
obliged to pay pretty stiff price for all
that 1t imports.
Every civilized country. however. should
be almost If not quite as much Interested
in this discovery as Germany, and for the
reason that 1t is likely to play prominent
part in the future manufacture of gunpow-
der. dynamite and other explosives. Under
| Of war. would have to obtain the necessary
supply of nitre from Chile, but now. thanks
TO Professor Oswald. she can obtain as
| much nitric acid as she wants and at i
nominal cost, for ammonia is very cheap,
and nothing else is required except air.
The same holds true to an almost equal
| extent of other countries: for Chile may be
nitre.'' +,
ARTIST, MUSICIAN AND AUTHOR.
Although he is rightly regarded in Ger
many. and, indeed, by all scientists as a
| chemist of the highest rank, Professor Os-
valid has also distinguished himself in other
| directions. Thus he is an excellent painter.
| a good musician and an author of wide
| repute. AS professor of high esteem in
which he is held throughout Europe and
| America, 1t is worthy of note that ever
! since he began to lecture in Leipzig more
F., than 25 Fer cent Of his pupils have been
Americans. Thus he has at present forty
| pupils. of which twenty-three are foreigners
I and Of the latter eleven are natives of this
! country,