Reps John William (61 results)

Author
Refine with Advanced Search

Refine your search

  • Books (61)

to

Custom price range (US$)

to

  • Language: English

    Published by Washington State Univ Pr, 1984

    0874220165 / 9780874220162

    • Hardcover

    Seller: Wonder Book, Frederick, MD, U.S.A.Wonder Book

    5-star seller
    Contact seller

    Association member: ABAAILAB

    Condition: New

    US$ 7.56

     Free Shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Condition: New. New dust jacket.

  • Language: English

    Published by University of North Carolina Press, Chapel Hill, 1991

    0807819484 / 9780807819487

    • Hardcover

    Seller: Fox and Tome Booksellers, Frederick, MD, U.S.A.Fox and Tome Booksellers

    4-star seller
    Contact seller

    Condition: Used - Very good

    US$ 12.26

     Free Shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardback. Condition: Very Good. hardcover with dust jacket, A nice copy. No writing or highlighting. Clean pages, shows very minimal signs of wear from use. Shipped with care in a bubble mailer. Feel free to inquire for photos or more details. Hand inspected item, complete, with minimal wear, guaranteed to pay or your money back. --- John W. Reps charts the visual and architectural evolution of Washington, D.C., from its founding in 1790 through the late twentieth century, drawing on more than 170 illustrations including engravings, aquatints, lithographs, watercolors, maps, and photographs that documented the capital before and after the advent of photography. The oversized volume reproduces images originally circulated in periodicals, guidebooks, souvenir publications, and as standalone prints, paired with commentary by travelers and residents recording their reactions to the growing city. Reps, a noted urban historian at Cornell, situates these depictions within the planning history of the District and the changing perceptions of the American capital.

  • Language: English

    Published by Amon Carter Museum of Western Art,, Fort Worth, TX, 1976

    088360051X / 9780883600511

    • Softcover
    • First Edition

    Seller: LEFT COAST BOOKS, Santa Maria, CA, U.S.A.LEFT COAST BOOKS

    5-star seller
    Contact seller

    Condition: Used - Very good

    US$ 14.50

     Free Shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Paperback. Condition: Very Good. 1st. 99 pages, illustrations (some colour); 22 x 28 cm. Exhibition presented at Amon Carter Museum of Western Art, Fort Worth, August 27 to October 10, 1976. Firm binding, clean inside copy. Light shelfwear to wraps. Age toning, edges lightly soiled. *** "City views and bird's eye views of selected cities provide examples of 19th century toned and hand colored lithography." - Publisher. Size: Oblong.

  • Language: English

    Published by Princeton University Press, 1967

    0691045275 / 9780691045276

    • Hardcover
    • First Edition

    Seller: Paradou Books, Richmond, VA, U.S.A.Paradou Books

    5-star seller
    Contact seller

    Condition: Used - Very good

    US$ 10.95

    US$ 3.95 shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardcover. Condition: Very Good. Dust Jacket Condition: Good. 1st Edition. Hardcover, with dust jacket. 221 pgs. 10.5 x 9 in. VG+ in good dj with corner/edge wear.

  • Language: English

    Published by Princeton University Press, 2022

    0691045275 / 9780691045276

    • Hardcover

    Seller: Better World Books, Mishawaka, IN, U.S.A.Better World Books

    5-star seller
    Contact seller

    Condition: Used - Good

    US$ 14.90

     Free Shipping 
    Ships within U.S.A.

    Quantity: 3 available

    Condition: Good. Former library copy. Pages intact with minimal writing/highlighting. The binding may be loose and creased. Dust jackets/supplements are not included. Includes library markings. Stock photo provided. Product includes identifying sticker. Better World Books: Buy Books. Do Good.

  • Language: English

    Published by Princeton University Press, 1970

    0691005753 / 9780691005751

    • Softcover

    Seller: Better World Books: West, Reno, NV, U.S.A.Better World Books: West

    5-star seller
    Contact seller

    Condition: Used - Good

    US$ 15.99

     Free Shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Condition: Good. Former library copy. Pages intact with minimal writing/highlighting. The binding may be loose and creased. Dust jackets/supplements are not included. Includes library markings. Stock photo provided. Product includes identifying sticker. Better World Books: Buy Books. Do Good.

  • Language: English

    Published by Princeton University Press, 1970

    0691005753 / 9780691005751

    • Softcover

    Seller: ThriftBooks-Dallas, Dallas, TX, U.S.A.ThriftBooks-Dallas

    5-star seller
    Contact seller

    Condition: Used - Fair

    US$ 16.08

     Free Shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Paperback. Condition: Fair. No Jacket. Readable copy. Pages may have considerable notes/highlighting. ~ ThriftBooks: Read More, Spend Less.

  • Language: English

    Published by Univ of Missouri Pr, Chicago, Illinois, U.S.A., 1994

    0826209394 / 9780826209399

    • Hardcover
    • First Edition

    Seller: Lazy S Books, Austin, TX, U.S.A.Lazy S Books

    4-star seller
    Contact seller

    Condition: Used - Good

    US$ 10.00

    US$ 7.00 shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardcover. Condition: Good. Dust Jacket Condition: Good. First Edition. An ex-library copy of a depiction of the cities along the Mississippi. Typical library markings but the interior is clean and nice. A reader that might spruce up with some care. A very heavy (>5#), oversize book that will require additional postage.

  • Language: English

    Published by Washington State University Press, Pullman, WA, 1984

    0874220165 / 9780874220162

    • Hardcover
    • First Edition

    Seller: LEFT COAST BOOKS, Santa Maria, CA, U.S.A.LEFT COAST BOOKS

    5-star seller
    Contact seller

    Condition: Used - Near fine

    US$ 19.50

     Free Shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardcover. Condition: Near Fine. Dust Jacket Condition: Very Good. 1st. Cloth, 93 pages, illustrations (some colour); 21 x 26 cm. Sherman and Mabel Smith Pettyjohn Lectures in Pacific Northwest History. Firm binding, clean inside copy. Age toning. Dust jacket with surface rubbing. *** "Beginning with Henry James Warre's view of Oregon City in 1846 and concluding with highly technical panoramas of Seattle and Portland by artists like E. S. Glover and Augustus Koch, John Reps demonstrates what lithographs of Pacific Northwest communities can tell us about the past. The text is illustrated by 44 beautiful, detailed drawings, eight in color." - Publisher. Size: Oblong.

  • Language: English

    Published by Princeton University Press, 2022

    0691045275 / 9780691045276

    • Hardcover

    Seller: Better World Books Ltd, Dunfermline, United KingdomBetter World Books Ltd

    5-star seller
    Contact seller

    Condition: Used - Good

    US$ 17.20

    US$ 6.67 shipping 
    Ships from United Kingdom to U.S.A.

    Quantity: 1 available

    Condition: Good. Former library copy. Pages intact with minimal writing/highlighting. The binding may be loose and creased. Dust jackets/supplements are not included. Includes library markings. Stock photo provided. Product includes identifying sticker. Better World Books: Buy Books. Do Good.

  • Language: English

    Published by Princeton Architectural Press October 1998, 1998

    1568981465 / 9781568981468

    • Hardcover

    Seller: Hennessey + Ingalls, Los Angeles, CA, U.S.A.Hennessey + Ingalls

    4-star seller
    Contact seller

    Condition: Used - Very good

    US$ 19.95

    US$ 7.50 shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardcover. Condition: Used - Very Good. As new towns and cities spread across the American frontier in the nineteenth century, itinerant artists soon followed, documenting these growing urban centers by drawing aerial perspectives, also known as bird's eye views. Commissioned by land speculators, local businesses, civic organizations, and individual citizens, these renderings fostered both civic pride and local commerce. The use of color lithography, a recent invention popularized by such prominent publishers as Currier &Ives, allowed the inexpensive reproduction of the highest-quality drawings, so that a bird's eye view was within the financial budget of even the smallest towns. These extraordinarily detailed lithographs eventually numbered in the thousands and now serve as a rich pictorial record of North America as it stood a century ago. This sequel to our highly acclaimed title 'An Atlas of Rare City Maps' collects over 100 views dating between 1835 and 1902, showing the streets, buildings, churches, bridges, waterways, and surrounding countryside of North American towns, ranging from burgeoning metropolitan centers to small logging towns and mining camps. Baltimore, Brooklyn, Denver, Indianapolis, Memphis, Montreal, New Orleans, Pittsburgh, Seattle, Syracuse, and Washington are just a few of the cities presented in this collection. The exquisite color and fine detail of these bird's eye views have been reproduced in all their original glory; also included is an introduction by John W. Reps providing a background on the artistic process and on urban development in the nineteenth century. Open copy with light wear, clean pages with tight binding, wrapped in Brodart protector.

  • Language: English

    Published by Princeton Architectural Press October 1998, 1998

    1568981465 / 9781568981468

    • Hardcover

    Seller: Hennessey + Ingalls, Los Angeles, CA, U.S.A.Hennessey + Ingalls

    4-star seller
    Contact seller

    Condition: Used - Very good

    US$ 20.00

    US$ 7.50 shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardcover. Condition: Used - Very Good. As new towns and cities spread across the American frontier in the nineteenth century, itinerant artists soon followed, documenting these growing urban centers by drawing aerial perspectives, also known as bird's eye views. Commissioned by land speculators, local businesses, civic organizations, and individual citizens, these renderings fostered both civic pride and local commerce. The use of color lithography, a recent invention popularized by such prominent publishers as Currier &Ives, allowed the inexpensive reproduction of the highest-quality drawings, so that a bird's eye view was within the financial budget of even the smallest towns. These extraordinarily detailed lithographs eventually numbered in the thousands and now serve as a rich pictorial record of North America as it stood a century ago. This sequel to our highly acclaimed title 'An Atlas of Rare City Maps' collects over 100 views dating between 1835 and 1902, showing the streets, buildings, churches, bridges, waterways, and surrounding countryside of North American towns, ranging from burgeoning metropolitan centers to small logging towns and mining camps. Baltimore, Brooklyn, Denver, Indianapolis, Memphis, Montreal, New Orleans, Pittsburgh, Seattle, Syracuse, and Washington are just a few of the cities presented in this collection. The exquisite color and fine detail of these bird's eye views have been reproduced in all their original glory; also included is an introduction by John W. Reps providing a background on the artistic process and on urban development in the nineteenth century. wrapped in complimentary Brodart dust jacket protector. Very nice clean, tight copy free of any marks.

  • More images

    Language: English

    Published by Princeton University Press, Princeton, 1967

    0691045275 / 9780691045276

    • Hardcover
    • First Edition

    Seller: Dale A. Sorenson, Silver Spring, MD, U.S.A.Dale A. Sorenson

    5-star seller
    Contact seller

    Association member: IOBA

    Condition: Used - Fine

    US$ 23.00

    US$ 6.00 shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardcover. Condition: Fine. Dust Jacket Condition: Very Good. First Edition. Princeton: Princeton University Press, 1967. First Edition. Oblong, 9" x 10.5". xv,221pp, Index, Bibliography, Notes on Illustrations. Blue cloth, spine letters gilt. Book in fine condition, dj very good (moderately worn at edges, price-clipped). With 101 illustrations. ; Oblong, 9 x 10.5 inches; 221 pages.

  • Language: English

    Published by University of North Carolina Press, Chapel Hill, NC, 1991

    0807819484 / 9780807819487

    • Hardcover
    • First Edition

    Seller: LEFT COAST BOOKS, Santa Maria, CA, U.S.A.LEFT COAST BOOKS

    5-star seller
    Contact seller

    Condition: Used - Very good

    US$ 29.50

     Free Shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardcover. Condition: Very Good. Dust Jacket Condition: Very Good. 1st. Cloth, xi, 297 pages, illustrations (some colour), maps (some colour); 30 x 39 cm. Firm binding, clean inside copy. Front free endpaper (blank) slightly scuffed from label removal. Dust jacket a little sun-faded along the foreedge of the front cover. OVERSIZE! Additional shipping charges may be requested for international & priority orders. A massive coffee-table book. Richly illustrated with colour plates. Size: Oblong. Collectible.

  • Language: English

    Published by Univ of Missouri Pr, Columbia, Missouri, U.S.A., 1994

    0826209394 / 9780826209399

    • Hardcover

    Seller: Alphaville Books, Inc., Hyattsville, MD, U.S.A.Alphaville Books, Inc.

    4-star seller
    Contact seller

    Condition: Used - Very good

    US$ 25.00

    US$ 5.00 shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hard Cover. Condition: Very Good. Dust Jacket Condition: Very Good. Very clean.

  • Language: English

    Published by Colonial Williamsburg Foundation, 1972

    0910412871 / 9780910412872

    • Hardcover

    Seller: Better World Books, Mishawaka, IN, U.S.A.Better World Books

    5-star seller
    Contact seller

    Condition: Used - Very good

    US$ 31.84

     Free Shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Condition: Very Good. Former library copy. Pages intact with possible writing/highlighting. Binding strong with minor wear. Dust jackets/supplements may not be included. Includes library markings. Stock photo provided. Product includes identifying sticker. Better World Books: Buy Books. Do Good.

  • Language: English

    Published by CW, Williamsburg, 1972

    0910412871 / 9780910412872

    • Hardcover
    • First Edition

    Seller: Reader's Corner, Inc., Raleigh, NC, U.S.A.Reader's Corner, Inc.

    5-star seller
    Contact seller

    Condition: Used - Near fine

    US$ 30.00

    US$ 5.50 shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardcover. Condition: Near Fine. Dust Jacket Condition: Very Good. First Edition. This is a near fine, hardcover first edition copy in blue/gray cloth binding in a mylar protected DJ . Blue spine. MEDIA SHIPPING ONLY, extra for airmail or international shipping.

  • Published by Princeton University Press, 1967

    • Hardcover

    Seller: Jeffrey Blake, Willow Grove, PA, U.S.A.Jeffrey Blake

    3-star seller
    Contact seller

    Condition: Used - Very good

    US$ 23.40

     Free Shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Add to basket

    Oversized Hardback. Condition: Very good condition. No dust jacket. 221p. B&W Photographs and Illustrations (illustrator).

  • Language: English

    Published by Colonial Williamsburg Foundation, Williamsburg, Virginia, U.S.A., 1972

    0910412871 / 9780910412872

    • Hardcover

    Seller: Gold Beach Books & Art Gallery LLC, Gold Beach, OR, U.S.A.Gold Beach Books & Art Gallery LLC

    5-star seller
    Contact seller

    Condition: Used - Very good

    US$ 30.00

    US$ 6.00 shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardcover. Condition: Very Good Minus. Dust Jacket Condition: Good Plus. xii, 345 pages; beige cloth boards with blue cloth spine; gilt spine titles; black & white illustrations, charts, and maps throughout; laid-in is a letter dated August 14, 1972 from a representative of the Colonial Williamsburg Foundation (publisher) announcing the book's publication; dust jacket with map of Tidewater area on front (not price-clipped); ever so slight shelf wear to boards; a bit of darkening to edges, with slight spotting to pages and minor rusting to top edge; some shelf wear to jacket (in protective mylar cover) with chipping and some small closed tears; minor dampstaining to inside upper rear of jacket; a very good minus to very good copy in a good plus jacket; a tight, clear example of this volume of interest to historians of the Colonial Chesapeake Bay area.

  • Language: English

    Published by Fort Worth, Tex. : Amon Carter Museum of Western Art, 1976

    088360051X / 9780883600511

    • Softcover
    • First Edition

    Seller: Joseph Burridge Books, Dagenham, United KingdomJoseph Burridge Books

    5-star seller
    Contact seller

    Condition: Used - Very good

    US$ 6.87

    US$ 30.69 shipping 
    Ships from United Kingdom to U.S.A.

    Quantity: 2 available

    Soft cover. Condition: Very Good. 1st Edition. 99 pages : Illustrations ; 21 x 28 cm. Amon Carter Museum of Western Art, Fort Worth, August 27 - October 10, 1976.

  • Language: English

    Published by Princeton University Press, Princeton, 1969

    0691005753 / 9780691005751

    • Hardcover
    • First Edition

    Seller: Ocean Tango Books, Palm Springs, CA, U.S.A.Ocean Tango Books

    4-star seller
    Contact seller

    Condition: Used - Very good

    US$ 35.00

    US$ 5.50 shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardcover. Condition: Very Good. Dust Jacket Condition: Very Good. 1st Edition. DUST JACKET as pictured First edition Very good condition hardcover nice dust jacket, price clipped gently read clean pages.

  • Language: English

    Published by Colonial Williamsburg Foundation; distributed by the University Press of Virginia, Charlottesville, Charlottesville, VA, 1972

    0910412871 / 9780910412872

    • Hardcover

    Seller: RW Books, Strasburg, VA, U.S.A.RW Books

    5-star seller
    Contact seller

    Condition: Used - Very good

    US$ 35.00

    US$ 5.95 shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardcover. Condition: Very Good. Dust Jacket Condition: Good. Owner's name inside, otherwise Very Good condition. Dust jacket Good only with edge wear, closed tears and rubbing. 345 pages with index, bibliography and numerous black & white maps and illustrations. Size: 8vo - over 7¾" - 9¾" tall.

  • Language: English

    Published by Princeton University Press, 1979

    0691046484 / 9780691046488

    • Hardcover
    • First Edition

    Seller: Jay W. Nelson, Bookseller, IOBA, Austin, MN, U.S.A.Jay W. Nelson, Bookseller, IOBA

    5-star seller
    Contact seller

    Association member: IOBA

    Condition: Used - Near fine

    US$ 42.00

    US$ 2.75 shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardcover. Condition: Near Fine. No Jacket. 1st Edition. No jacket. Light wear to slipcase.

  • Language: English

    Published by Univ of North Carolina Pr, Chapel Hill, North Carolina, U.S.A., 1991

    0807819484 / 9780807819487

    • Hardcover

    Seller: Alphaville Books, Inc., Hyattsville, MD, U.S.A.Alphaville Books, Inc.

    4-star seller
    Contact seller

    Condition: Used - Very good

    US$ 40.00

    US$ 5.00 shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hard Cover. Condition: Very Good. Dust Jacket Condition: Very Good. Bumped at base of both boards. Otherwise clean, bright, tight and sound.

  • Language: English

    Published by Princeton University Press, 1979

    0691046484 / 9780691046488

    • Hardcover

    Seller: ThriftBooks-Atlanta, AUSTELL, GA, U.S.A.ThriftBooks-Atlanta

    5-star seller
    Contact seller

    Condition: Used - Fair

    US$ 45.73

     Free Shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardcover. Condition: Fair. No Jacket. Former library book; Missing dust jacket; Readable copy. Pages may have considerable notes/highlighting. ~ ThriftBooks: Read More, Spend Less.

  • Language: English

    Published by Missouri Historical Society Press, Saint Louis, Missouri, U.S.A., 2006

    1883982553 / 9781883982553

    • Hardcover
    • First Edition

    Seller: Granada Bookstore, IOBA, Woodlawn, IL, U.S.A.Granada Bookstore, IOBA

    5-star seller
    Contact seller

    Association member: IOBA

    Condition: Used - Very good

    US$ 39.99

    US$ 6.99 shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardcover. Condition: Very Good. Dust Jacket Condition: Very Good. 1st Edition. First Edition (Number Line Starting At One). Includes Bibliographical References And Index. The Book Is Bound In Blue Cloth With Silver Stamped Lettering On The Spine. Light Bumping To Three Corners. Tiny 2 Written Near The Upper Corner Of The Front Pastedown. The Jacket Has Minor Wear And Some Light Scratches On The Back.

  • Language: English

    Published by Princeton University Press, 1979

    0691046484 / 9780691046488

    • Hardcover

    Seller: Vintage Books and Fine Art, Oxford, MD, U.S.A.Vintage Books and Fine Art

    5-star seller
    Contact seller

    Condition: Used - Very good

    US$ 40.00

    US$ 8.50 shipping 
    Ships within U.S.A.

    Quantity: 1 available

    hardcover. Condition: Very Good. Square tight binding. Clean interior, save for previous owner blind stamp to lower front endpaper with tiny date and location handwritten within . Original slipcase included. Little wear to binding or slipcase, save for some light sunning around slip case edges.

  • Published by The Colonial Williamsburg Foundation, 1972

    0813903327 / 9780813903323

    • Hardcover
    • First Edition

    Seller: Graver & Pen Rare Books, Midland, MI, U.S.A.Graver & Pen Rare Books

    5-star seller
    Contact seller

    Condition: Used - Very good

    US$ 27.50

    US$ 5.00 shipping 
    Ships within U.S.A.

    Quantity: 1 available

    Hardcover. Condition: Very Good. No Jacket. 1st Edition. signed by previous owner, else very good.

  • Language: English

    Published by New York : Princeton Architectural Press, 1998

    1568981465 / 9781568981468

    • Hardcover
    • First Edition

    Seller: MW Books, New York, NY, U.S.A.MW Books

    5-star seller
    Contact seller

    Condition: Used

    Original price: US$ 59.94
    15% off

    Current price: US$ 50.95

     Free Shipping 
    Ships within U.S.A.

    Quantity: 3 available

    First Edition. Fine copy in the original title-blocked cloth. Spine bands and panel edges very slightly dust-toned as with age. Corners sharp with an overall tight, bright and clean impression.; 8vo 8" - 9" tall; 98 pages; Description: 98 p. : col. ill. ; 32 x 38 cm. Subjects: City and town life in art --Lithography, American --19th century --United States --Canada --In art. Summary: As new towns and cities spread across the American frontier in the nineteenth century, itinerant artists soon followed, documenting these growing urban centers by drawing aerial perspectives, also known as bird's eye views. Commissioned by land speculators, local businesses, civic organizations, and individual citizens, these renderings fostered both civic pride and local commerce. The use of color lithography, a recent invention popularized by such prominent publishers as Currier & Ives, allowed the inexpensive reproduction of the highest-quality drawings, so that a bird's eye view was within the financial budget of even the smallest towns. These extraordinarily detailed lithographs eventually numbered in the thousands and now serve as a rich pictorial record of North America as it stood a century ago. This sequel to our highly acclaimed title An Atlas of Rare City Maps collects over 100 views dating between 1835 and 1902, showing the streets, buildings, churches, bridges, waterways, and surrounding countryside of North American towns, ranging from burgeoning metropolitan centers to small logging towns and mining camps. Baltimore, Brooklyn, Denver, Indianapolis, Memphis, Montreal, New Orleans, Pittsburgh, Seattle, Syracuse, and Washington are just a few of the cities presented in this collection. The exquisite color and fine detail of these bird's eye views have been reproduced in all their original glory; also included is an introduction by John W. Reps providing a background on the artistic process and on urban development in the nineteenth century. 2 Kg.

  • Language: English

    Published by Princeton University Press, 1979

    0691046484 / 9780691046488

    • Hardcover

    Seller: Phatpocket Limited, Waltham Abbey, HERTS, United KingdomPhatpocket Limited

    5-star seller
    Contact seller

    Condition: Used - Good

    US$ 41.22

    US$ 14.20 shipping 
    Ships from United Kingdom to U.S.A.

    Quantity: 1 available

    Condition: Good. Book is VG in slightly worn slipcase. Your purchase helps support Sri Lankan Children's Charity 'The Rainbow Centre'. Ex-library, so some stamps and wear, but in good overall condition. Our donations to The Rainbow Centre have helped provide an education and a safe haven to hundreds of children who live in appalling conditions.