RETURN to the CHEM 498C Home Page
Chemistry on the Internet
Prof. Thomas C. O'Haver
Department of Chemistry and Biochemistry
University of Maryland
College Park, MD 20742
Phone: (301) 4051831
http://www.wam.umd.edu/~toh/
to2@umail.umd.edu
This document describes the main Internet information access tools and lists
some of the sites that have chemistry and other science-related material.
Listserv discussion lists
If you have an e-mail account, you can participate in e-mail discussion groups
called "listserv lists". There are several in the chemistry area:
CHEMED-L@UWF.CC.UWF.EDU Chemistry Education
CHMINF-L@iubvm.BITNET Chemical information sources
CHEMCORD@UMDD.UMD.EDU General Chem. Coordinators Discussion
CHEMCONF@UMDD.UMD.EDU Scheduled online chemistry conferences
CHEMCOM@UBVM.BITNET Chemistry in the Community Discussion
CHEME-L@PSUVM.BITNET Chemical Engineering
ICS-L@UMDD.UMD.EDU International Chemometrics Society
(The part before the @ sign is the list name and the part after the @
sign is the host address). The general method for subscribing to most
listserv lists is to send a message to LISTSERV@hostaddress in which the first
line of the message body is "SUB listname yourname", where
listname is the name of the list and yourname is your full name.
For example, if you want to subscribe to the chemical education list and your
name is John Doe, send a one-line email message to
LISTSERV@UWF.CC.UWF.EDU, with a blank subject line, containing the
message "sub CHEMED-L John Doe". Once your subscription is
procsessed, you would send messages to the list by sending them to the list
address (e.g. to CHEMED-L@UWF.CC.UWF.EDU. To unsubscribe (cancel your
subscription), send the message "signoff CHEMED-L" to
LISTSERV@UWF.CC.UWF.EDU.
Most listserv lists save all their past messages and allow you to search for
messages that mention a specific keyword. For example, if you want to know if
anyone in the CHEMED-L list has ever mentioned, say, benzene, send the
following 6-line message to LISTSERV@UWF.CC.UWF.EDU:
//
Database Search DD=Rules
//Rules DD *
Search benzene in CHEMED-L
Print all
/*
The LISTSERV host will send to you by return e-mail all messages that contain
the word benzene. You don't need to actually type this gibberish each time -
keep a copy in your computer's "Note Pad" and just edit it for your keyword and
Copy and Paste it into the outgoing mail message. (Note: you may not even have
to subscribe to a discussion list in order to be able to search it in this
manner).
The other listservs operate in the same manner; just substitute the name of the
list for CHEMED-L and the host name for UWF.CC.UWF.EDU in the above
example.
Usenet Newsgroups
Newsgroups are topic-specific discussion groups, also called netnews or just
news.
To access newsgroups from a networked computer (e.g. in a WAM or Open lab),
look for a Newsreader client such as InterNews. These local client
newsreaders have a point-and-click interface that you can generally figure out
by playing around. To access newsgroups when you are dialing in with a
conventional terminal program, type "tin" at the Unix system prompt and press
return. Press return until you get to the main screen that says Group
Selection at the top. If you know the name of a newsgroup you wish to look at
(e.g. sci.chem, which deals with chemistry), type "g sci.chem" and press
return. If you wish to find whether there is a newsgroup whose name contains a
certain keyword, press "y" to "yank" in all newsgroups, then type a "/"
followed by the keyword and the computer will search for any newsgroups whose
names contain that keyword. (Newsgroup names are usually abbreviated: e.g. sci
for science, bio for biology, edu for education; chem for chem istry, comp for
computer, etc.) Press / and return again to go to the next match. Press "s"
to subscribe to that group (i.e., add it to your Group Selection screen), "u"
to unsubscribe. To read a newsgroup, use the arrow keys to move in, out, up
and down. Press Q to quit. (Hint: "news.answers" has a good collection of
"frequently asked questions" documents).
Here is a list of some chemistry and science-related groups.
sci.chem Chemistry and related sciences
sci.chem.organomet Organometallic chemistry
sci.chem.electrochem Electrochemistry
sci.chem.labware Chemical labware
sci.edu Science education
bionet. Biological sciences (many sub-groups)
sci.physics. Physics (several sub-groups)
sci.med.physics Medical physics
alt.sci.physics. Physics (several sub-groups)
sci.engr.biomed Biomedical engineering
sci.engr.chem Chemical engineering
alt.internet.services Information about services available
news.announce.newusers Explanatory postings for new users
news.answers Repository for periodic USENET FAQs
Journal article search (UnCover).
At the Unix system prompt type "telnet victor", then "PAC", then "8", press
enter until you see the VICTOR main menu. Select
Journal Indexes/Article Delivery
UnCover (table of contents/article delivery).
Then enter the 14-digit barcode or OCR number from your library ID card and
follow the further on-screen instructions. UnCover searches operate just like
U. of Md. card catalog searches. These searches return bibliographic citations
but also offer to FAX articles to you at a cost of typically $8 -12 per article
(paid via credit card).
World Wide Web
World Wide Web is a global network of linked multimedia "hypertext"
documents. Each docu ment contains highlighted (underlined or color) words
that serve as "hot links" to other documents. You navigate through the
documents simply by selecting the links that interest you. The best way to
explore it is to use Netscape, a multimedia WWW brouser that supports embedded
graphics and sounds.
What is Netscape?
Netscape is currently the most popular graphical World Wide Web (WWW) browser
that is used to view, save, and print multimedia documents that are resident on
Web servers anywhere in the world. Netscape is free for academic users; it can
be downloaded from the Internet, or you can get a copy on diskette from one of
the book/disk combos on Internet and WWW found in the computer sections of
better bookstores.
How can I access Netscape?
Netscape is a "local client", a program that runs on your local desktop
computer and that accesses the Internet through some sort of network
connection. Netscape is easiest to use if your desktop computer is already
connected to a local area network (LAN) that has a "gateway" to the Internet.
If you are already using other "TCP/IP" clients, such as NCSA Telnet or or
Eudora, then it is likely that your are already connected in this way. In that
case, all you have to do is to put a copy of Netscape on your hard disk and
double-click on it.
Can I access the World Wide Web when I dial in to my UNIX shell account?
Probably. The most popular host-based text-mode Web client is "lynx". Just
type lynx at the host system prompt. If that does not work, ask your host
system administrator to install lynx or some other WWW client.
Can I access Netscape when I dial in to my UNIX shell account?
Not directly. But it can be done, with the right software. This process is more
complex that setting up Netscape on a LAN-connected computer, but it does give
you a way to use Netscape at home, where you (probably) do not have a LAN
gateway. Basically you'll need a "SLIP" or "PPP" account from your Internet
service provider, plus a couple of other pieces of software for your desktop
computer: e.g. Trumpet Winsock for Windows 3.1, Dialup Networking for Windows
95, or MacTCP and InterSLIP or MacPPP for Macintosh.
How do I use Netscape ?
Just click! Active "links" are shown as underlined blue text or icons with blue
outlines. Just click once on the link to follow it. Click the Back button to go
back to the previous page and Forward to move forward again. Internet sites are
described by an address in a standard form called a Universal Resource Locator
(URL). Web page URLs begin with "http://". For example,
http://www.wam.umd.edu/~toh/toh.html is a typical Web URL. To go to a specific
URL, use the Open Location... menu item in the File menu and type
or paste the URL into the resulting box. Saving and printing a Web page works
just like a word processor (Save and Print are in the File
menu). When you save you have the choice of "text" or "source". Use text if you
plan to import the text into a word processor; use source if you plan to open
up the file from within Netscape, using the Open File command.
Bookmarks
Bookmarks allow you to return easily to a previously-visited Web page. To
create a bookmark to the page you are on, select Add bookmark from the
Bookmark menu. This adds it to the Bookmarks menu (which gets longer and
longer). To go to a previous bookmark, just select it from the Bookmarks menu.
You can edit the bookmarks, delete them and change their names, by using the
Edit bookmarks item. Bookmarks are stored on that machine only; if you
access the Web from another computer, you will see a different set of
bookmarks.
Downloading graphics
Downloading graphics is much easier if you are using version 1.1 or later of
Netscape. In that case, just place the mouse pointer on the graphic, hold down
the mouse button, and select Save the Image as... from the menu that
pops up. This results in a standard "Save" dialog box. Alternatively, you can
Copy Image, and Paste it into another application. Saved graphics
are normally in GIF format, sometimes in JPG format. You can use a shareware
graphics program such as Graphic Converter (Mac) or LView
(Windows) to convert between formats.
Sounds and Video clips
Links to sound files (which usually have an ".au" or ".aiff" extension) can be
played through your computer's speakers if you have a "sound player"
application in the same folder as Netscape. A popular one for the Mac is
SoundMachine, which can be downloaded from various sources. Sound files
are often big. Links to digital video (movie) files, which usually have a
".mov" or ".mpg" extension, can be viewed if you have a "movie player"
application. Popular ones for the Mac are Simple Player (for Quicktime
movie) and Sparkle (for MPEG movies), both of which can be downloaded
from various sources. Movie files are usually very large. An alternative to
the use of separate helper applications is the use of Netscape plug-ins,
which are downloadable (or commercial) software add-ons to Netscape 2.0 that
allow multimedia content to be displayed directly on Web pages.
Extending Netscape for chemistry data types
Netscape has the ability to detect hypertext links to specialized data types
and to launch a specified helper program or plug-in to view that data. Henry
Rzepa of Imperial College (London) has exploited this idea in his online
conferences and presentations and has extend the list of recognized special
data types to include Adobe Acrobat files, molecular coordinates in ".pdb"
(Protein Data Bank) format, structure drawings in ISIS/Draw format, etc.
After installing the required helper programs or plug-ins (which for the above
data types are freeware programs that can be downloaded from the Internet), and
configuring Netscape accordingly, the user need only click on the hypertext
link and the data are automatically downloaded and visualized. This allows the
user to remain focused on the chemistry and not be distracted by the complexity
of downloading. Once you have Netscape installed and running, you can use it
to download helper applications and plug-ins for sound, video, molecular
visualization, chemical structures, etc. See
http://home.netscape.com/comprod/products/navigator/version_2.0/plugins/index.html
for the latest plug-ins for Netscape. A great
plug-in for chemistry is ChemScape Chime from MDL Information Systems
(see http://www.mdli.com/).
How can I create my own home page on the Web?
It's easier than it looks! Web pages are just text files that are "tagged" with
"HTML" symbols to represent structure and function. You can prepare Web pages
in any text editor or word processor. The system of tags is very logical and
easy to learn. Perhaps the easiest way to learn is to look at the "source text"
of existing pages - you can do this for any page on the Web just by selecting
Source from the View menu, which displays the source text with
all its tags in a separate window. Compare this to the rendered page in the
main Netscape window, copy the parts you want to, and you will begin to learn
in a practical way how it all works. For graphics, use a shareware graphics
program such as Graphic Converter (Mac) or LVIEW (Windows) to convert your
graphics into GIF or JPG format, then save them in the same directory as your
HTML text. Finally, you need to upload all your HTML and graphic files to a Web
server so they will be accessible worldwide. For more info see
http://www.wam.umd.edu/~toh/Handouts.html.
Using Netscape in Local mode
Netscape can open files stored on your hard disk or on a LAN file server, even
if it is not connected to the Internet, by using the Open File command.
Text files that contain "HTML" tags will be rendered just like an on-line Web
page. In this way you can test the formatting of Web pages that you or your
students are creating before they are submitted to the server. This works even
on a machine that is not actually hooked up to the 'net. In fact, Netscape can
be used an a simple but economical multi-platform multimedia delivery system -
it's free, available for Macs and PCs, uses the exact same file formats on all
platforms, and has the added benefit that the files are ready to go on-line
when you get space on a Web server.
Some useful URLs to get you started
The WWW is growing and changing so rapidly that it is impossible for a print
publication such as this newsletter to keep up to date. The following URLs
were checked for accuracy and were all operational on May 1, 1996. By the
time you read this, some of them may have changed and many new ones will
certainly exist. Although the Web is still very new, many chemists are already
beginning to exploit its capabilities for chemistry information and
education.
Use the Open Location... menu item in the File menu and type or
paste these URLs into the resulting box:
Chemistry and chemistry education
Internet Resources for Chemistry
http://www.wam.umd.edu/~toh/Chemistry.html
Sites "approved" by the Journal of Chemical Education
http://jchemed.chem.wisc.edu/JCEWWW/WWWReview.html
General collections of links
Very large collection of links, organized by subject
http://www.yahoo.com/
Large Collection of Science and Math Internet Resources
http://www.wam.umd.edu/~toh/MathScience.html
Software and instructions for Web construction and application
HTML Developers Reference Page
http://oneworld.wa.com/htmldev/devpage/dev-page.html
"How to Make a Web Page", a hypermedia tutorial
http://www.wam.umd.edu/~toh/HowToMakeAWebPage.html
Macintosh software to access the Web
http://forum.swarthmore.edu/workshops/workshop.software.html
PC software to access the Web
http://forum.swarthmore.edu/workshops/pc.html
http://ac.dal.ca/~dong/table.htm
Graphics programs for both platforms
http://www.public.iastate.edu/~stark/gutil_sv.html
Sound players and related programs
http://www.wavenet.com/~axgrindr/quimby4.html
Converting various file formats for use on various platforms
http://www.mps.org/~ebennett/
Educational application of the Web
http://hakatai.mcli.dist.maricopa.edu/authoring/index.html
http://ccat.sas.upenn.edu/teachdemo
http://www.covis.nwu.edu/Papers/k12web.html
Notes:
1. You can have multiple TCP/IP local clients running simultaneously; e.g.
you can be running Telnet and Netscape at the same time, if your machine has
enough RAM memory available.
2. Netscape can have more than one window open at a time, each one accessing
a different Web site. Select New from the File menu to generate another
window.
3. Netscape has built-in help files and even a User's Manual; see the Help
menu.
File Transfer Protocol (FTP)
FTP is a method of downloading (receiving) files from remote computers to your
local machine and for uploading (sending) files your local machine to a remote
computers over the Internet. You can perform FTP using either a host-based
client program (e.g. the "ftp" command in Unix) or a local client such as Fetch
for the Mac or WS_FTP.EXE for the PC. There is an important difference between
using a host-based and a local FTP client: using a host-based program transfers
files to and from the file space on your Unix account, whereas using a local
client transfers files to and from the file space on your desktop PC's hard
disk.
Many host system run by academic and government organizations run FTP servers
that allow "anonymous" access to certain files, allowing anyone to download
them. You don't actually have to have an FTP client program just to download
files from anonymous FTP servers; it can also be done quite conveniently from
Netscape. On the other hand, uploading files (e.g. from your desktop PC
to your WAM account space) requires either an FTP client program or the use of
"zmodem" or "kermit" (file transfer protocols that work over ordinary dial-up
connections). See
http://www.inform.umd.edu/UMS+State/UMD-Projects/MCTP/Technology/software.html
for a collection of links to downloadable science and chemistry software.
Software Sources
Local clients for gopher, WWW (e.g. Netscape), FTP, Netnews, and e-mail are
available commercially, as freeware and shareware (which can be downloaded from
the Internet without charge), and on floppy disks and CD-ROMs that come with
some books about the Internet. Check out the computer section of your local
bookstore.
This page is maintained by Tom O'Haver , Department of Chemistry and
Biochemistry, The University of Maryland at College Park.
Comments, suggestions and questions should be directed to
Prof. O'Haver at to2@umail.umd.edu.