t



U. S. DEPARTMENT OF COMMERCE

DANIEL C. ROPER, Secretary BUREAU OF STANDARDS

LYMAN J. BRIGGS, ActinS Director BUREAU OF STANDARDS MISCELLANEOUS PUBLICATION No. 140 A STUDY

OF THE DETERIORATION OF BOOK PAPERS

IN LIBRARIES

By ARTHUR E. KIMBERLY

ADELAIDE L. EMLEY

Issued April 6, 1933

UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1933 For sale by the Superintendent of Documents, Washington, D. C. - - - - Price 5 cents

A STUDY OF THE DETERIORATION OF BOOK PAPERS IN

LIBRARIES 1 By Arthur E. Kimberly 2 and Adelaide L. Emley 2 ABSTRACT

The examination of paper from identical books submitted by city and country

or suburban libraries disclosed that paper from books stored in urban insti- tutions is uniformly more deteriorated than that from identical volumes

kept in country libraries. The poorer condition of the city books is shown

by their higher acidity, lower alpha cellulose content, higher copper number, and lower folding endurance. Since the papers from books stored in urban

localities had high acid contents and showed the type of chemical deterioration of fiber that occurs when papers are exposed to air containing small amounts of sulphur dioxide gas, it was concluded that their greater deterioration was mainly due to this fuel combustion product. Papers containing chemically refined rag and wood fibers were found invari- ably to be in better condition than papers containing appreciable quantities

of ground wood fibers. This serves to emphasize the importance of the chemical purity of the fibers themselves as a factor in paper permanence. Data are given on the kinds of fibers found in the book papers as related

to the dates of the publications. Since the dates cover the transition from

use of rag fibers alone to use of straw and wood fibers also, these data are

of historical interest in the use of fibers for book papers. They also define a period, 1875-1910, during which crude fibers were frequently used in book

papers, and thus serve as a warning that the papers in books published

in this period may be quite impermanent.

CONTENTS

Page

I. Introduction 1

II. Method of collecting specimens 2

III. Inspection and testing of specimens 2

IV. Results 3

V. Discussion of results 5

VI. Summary 7

VII. Acknowledgment. _ 7 L INTRODUCTION

The deterioration of the paper contained in books has been a source of worry to librarians and archivists for over a century. As early as 1823, in an article in the Gentleman's Magazine of London, John Murray deplored the disintegration of paper produced

prior to that time and in a later publication suggested means of improving the lasting qualities of paper. Since then the problem

1 This is one of a series of investigations concerning the preservation of -written and

printed records which is being made at the Bureau of Standards with the assistance of a fund granted for the purpose by the Carnegie Corporation to the National Research

Council.

2 Research associate representing the National Research Council. 165258°—33 1
2 MISCELLANEOUS PUBLICATIONS, BUREAU OF STANDARDS

of paper preservation has become increasingly important until to- day it is a matter of great concern to all those interested in the permanence of records. A recent survey of storage conditions in libraries 8 showed that books and manuscripts stored in the average library are not well protected against the effects of such " external " agencies of deterio- ration as air polluted by acid gases,45 and changing temperature

and humidity.67 Moreover, consultation with librarians in dif- ferent localities indicated a belief that books stored in city institu- tions deteriorated more rapidly than similar volumes kept in country

or suburban localities, even though the wear and tear incident to use was approximately the same for each depository. It, therefore, ap- peared to be of value to compare the effect of city storage versus county storage upon similar books and also to ascertain the relative

state of preservation of different kinds of book papers. In view

of data on air pollution 8 previously considered it would not be

surprising if a book which had been exposed to an urban atmosphere,

contaminated by acid gases, deteriorated to a greater extent than a

similar book stored in a country or suburban locality relatively free from air pollution. In order to study these problems the cooperation of representative libraries throughout the United States was

invited.

II. METHOD OF COLLECTING SPECIMENS

Through the courtesy of the New York Public Library a group

of 34 deteriorated books was obtained for complete examination.

A list of these books was then sent to libraries throughout the United

States with the request that they forward duplicates for examination,

whether deteriorated or not. They were further requested to send any other books which showed a definitely good or bad state of preservation and which could be spared for examination. By this means, 229 books published during the period 1720-1930, as well

as 85 duplicates of 31 different titles were collected from 23 libraries in widely separated localities. III. INSPECTION AND TESTING OF SPECIMENS

The similar books were carefulty inspected to insure uniformity

of edition and date of printing, and the records of the contributing

institutions were checked so as to include for examination only

these books which had been subjected to approximately the same

degree of use while in circulation. This final process of selection yielded a group of 11 titles, each represented by 2 or more volumes. The paper of these was carefully inspected for state of preservation

and then subjected to thorough chemical and physical analyses, the same portion of each different book being tested to insure absolute

similarity of samples.

3 Kimberly, Arthur K, and Hicks, J. F. G. jr., B. S. Misc. Pub. No. 128.

4 Richter, George A., Ind. and Eng. Chem., vol. 23, No. 4, p. 371, 1931.

B Kimberly, Arthur E., B. S. Jour. Research, vol. 8, p. 159, 1932.

6 Norris, J., Library J., vol. 38, p. 16, 1913.

7 Brauns, O., Pulp Paper Mag. Can., vol. 26, pp. 11, 165, 1928.

8 See footnote 3.
DETERIORATION OF BOOK PAPERS IN LIBRARIES 3 The alpha cellulose content and copper number of these books were determined by modified procedures developed by the bureau

specifically for testing paper.9 The alpha cellulose content of any

paper is that part of the cellulosic material which is insoluble in a sodium hydroxide solution of mercerizing strength (17.5 per cent NaOH) under certain specified conditions, and is regarded as a measure of the amount of unmodified cellulose which the material

contains. A high alpha cellulose content is considered an indication of superior condition in paper. The copper number, on the other hand, is a measure of the amount of modified or deteriorated cellu- lose present and, when high, is regarded as an indication of poor

condition in paper. The procedure for determining the acidity of

these specimens was the one selected for use in the investigation of

the effect of sulphur dioxide on paper.10 The M. I. T. folding en- durance tester, a device by means of which a strip of paper under

tension is repeatedly folded upon itself until broken, was used throughout this work, as a significant number of double folds could be obtained on many of the deteriorated specimens only by the use of a very low tension, which is easily obtained in this tester. The

tension used was 300 g. All of the books, whether in the selected group of titles or not, were subjected to a determination of fiber composition according to the official methods of the Technical Association of the Pulp, and

Paper Industry. 11 The papers were then jointly graded by three persons into three classes with consideration of color and strength.

The specimens were said to be in good condition if there was no

apparent weakening of the fibers and no discoloration. They were graded in intermediate condition if somewhat discolored and embrittled, and rated in bad condition if they broke after creasing once with the fingers and were highly discolored. In the case of

identical volumes, care was taken to examine paper from the same

portion of each book. IV. RESULTS

Table 1 contains test data for 11 different titles, copies of which

were contributed by two or more libraries. The table also contains a statement as to whether the atmosphere in the vicinity of any

given library is polluted or relatively free from acid pollution, based upon a careful survey of the surroundings in person or by correspondence, when a personal survey was impracticable and upon what little data on air pollution that is now available. For example, the New

York Public Library is situated in the heart of New York City sur- rounded by high buildings, a condition under which one might expect

to encounter a marked degree of atmospheric pollution. Analyses

of air in this vicinity show 0.8 to 1.2 parts sulphur dioxide per

million parts of air. 12 Similarly the University of Pennsylvania

Library is located in down-town Philadelphia, bounded on one side by main-line railroad tracks and in close proximity to an oil refinery

9 Burton, J. O., and Rasch, R. H., B. S. Jour. Research, vol. 6, p. 603, 1931.

10 See footnote 5, p. 2.

11 Copies of the official paper testing methods of the Technical Association of the Pulp and Paper Industry may be obtained from the secretary at 370 Lexington Avenue, New

York, N. Y.

12 Communication from the Bell Telephone Laboratories.
4 MISCELLANEOUS PUBLICATIONS, BUREAU OF STANDARDS
DETERIORATION OF BOOK PAPERS IN LIBRARIES 5 and numerous chemical plants. The sulphur dioxide content of air in this vicinity was found to vary from 0.1 to 1.8 parts sulphur dioxide per 1,000,000 parts of air 13 and damage by sulphur dioxide to the foliage of elm trees in the university botanical gardens has been

observed by members of the university staff. With these highly

polluted localities may be contrasted that of Iowa State College

situated several miles from the down-town section of Ames, Iowa, in an area relatively free from industrial pollution. Table 2 shows the results of the visual examination of 129 books

published before 1911. This date was chosen in order to examine

only papers which had been in existence long enough for differences in relative stability to become apparent. The papers are divided into nine groups according to kinds of fibers. Data as to the oldest and

the most recent specimens of the various papers and the average age

of the specimens in each group are included in Table 2. Table 2.

Relation of state of preservation to kind of fiber

Rag and straw * Rag and chemical wood

Rag, chemical wood and straw * Chemical wood

Chemical wood and straw 4 Straw i Mixture containing 10 per cent or less ground wood

Mixture containing more than 10 per

cent ground wood

Date of oldest

speci- men

1804 1867

1870

1876

Date of most

recent

speci- men

1874 1878

1908 1910

1909

1910

1882

Average age

Good

condition 1 Number of papers

Per

cent

of

total

Intermediate

condition 2 Number of papers

Per

cent

of

total

1 No indication of weakening—color usually excellent.

2 Somewhat embrittled, giving indications of breaking when creased.

3 Very brittle, highly discolored.

4 Some or all of the fibers reported as straw may be esparto due to the difficulty of distinguishing between

these fibers. V. DISCUSSION OF RESULTS

The data in Table 1 show that books stored in libraries where the atmosphere is characteristically urban (for example, New York Public Library) contain more acid than other copies of the same books

stored in libraries where the atmosphere is less likely to be contami- nated (for example, Iowa State College). The data also show that

this increase in acidity is invariably accompanied by a decrease in the strength of the paper and characterized in most cases by an

increase in copper number and a decrease in alpha cellulose content,

all of which are indications of poor condition in paper. The principal difference between storage conditions in cities and

elsewhere, as shown by the survey of library storage conditions previously mentioned, 14 is the presence in urban air of measurable

quantities of sulphur dioxide. This gas, a product of the combustion

of fuel and of certain industrial processes, combines with moisture and

13 Information from University of Pennsylvania Botany Department.

14 See footnote 3, p. 2.
6 MISCELLANEOUS PUBLICATIONS, BUREAU OF STANDARDS

oxygen in the air to form sulphuric acid, which is known to be very

destructive to paper.15 The outstanding characteristic of paper which

has been exposed to an atmosphere containing sulphur dioxide is an

abnormally high acidity. This is illustrated in Table 3 which shows

the change in acid content of 3 different papers after natural aging

for 4 years in an atmosphere relatively free from sulphur dioxide,

and after 240 hours exposure to the action of 2 to 9 parts sulphur

dioxide per 1,000,000 parts of air at 65 per cent relative humidity

and 30° C. In each case the acidity of the specimen exposed to the

action of sulphur dioxide is markedly higher than that of the naturally aged sample. Since it has already been shown that the

acidity of books stored in large cities, such as New York and

Philadelphia, is usually considerably higher than that of similar books stored in country or suburban libraries and that sulphur

dioxide, which in the process of acting on paper produces high acidity in the paper, is present in the air of such cities, it seems reasonable

to ascribe the major portion of the greater deterioration noted in the books from city institutions to the action of sulphur dioxide. Table 3.

Increase in acidity of papers

Sample No.

Fiber composition Acidity

as sul- phuric an- hydride

Increase

in acidity Rag Sulphite

94011 - Per cent 100 100

10060

60

60

Per cent Per cent

0. 09 .10 .18

.08 .10

.16

.08

.12 .20

Per cent

94011; 4 years 1 11.

1

94011; SO2-240 2 100 94008 40

4040

100

100

100

94008; 4 years 1 25

94008; SO2-240 2 100 94010

94010; 4 years 1 50

94010; SO2-240 2 150

1 Naturally aged four years in an atmosphere relatively free from sulphur dioxide.

2 Treated for 240 hours with 2 to 9 parts sulphur dioxide per 1,000,000 parts of air, at 65 per cent relative humidity and 30° C. The results of this work emphasize further the necessity of elim- inating sulphur dioxide from library air, either by washing the incoming air with an alkaline solution as suggested in a previous

report,16 or by some other means. Work now in progress indicates that sulphur dioxide is completely removed by the alkaline wash

method.

The results of the examination of 129 books printed before 1911

are shown in Table 2 and indicate that the presence of more than

10 per cent ground wood fibers causes a marked decrease in the

resistance of paper to natural aging. This finding is in accord with work on present-day book papers 17 and adds to other evidence secured by the bureau of the importance of fiber purity for the

stability of such papers relative to internal sources of deterioration. The average age of the various groups of papers and the earliest

15 See footnotes 4 and 5, p. 2.

16 See footnote 3, p. 2.

17 Burton, J. O., B. S. Jour. Research, vol. 7. p. 429, 1931.
DETERIORATION OF BOOK PAPERS IN LIBRARIES 7

date for each group, given in Table 2, are of historical interest as they show the approximate time of initial use of the different types

of fibers in book papers. This information also serves as a warning

that many valuable books printed later than 1875 may contain impermanent papers made from crude fibers. Such fibers are rarely

found in important publications after 1910. A peculiarity observed

in some of the old books was the use of good and poor papers. In

several instances the best grades of paper were mixed with the poorest grades, which is one cause of the uneven deterioration of different pages often observed in old books. VI. SUMMARY

1. The paper of books printed at the same time on the same paper

does not deteriorate at the same rate, even though subjected to approximately the same degree of use.

2. The paper of books stored in libraries where the atmosphere is characteristically urban was invariably found to be less well pre- served than the paper of similar books stored in a less contaminated

atmosphere.

3. The greater deterioration of books stored in large cities is probably due to the harmful effect of contact with air polluted

by sulphur dioxide.

4. Papers containing appreciable quantities of crude fibers such as ground wood, were invariably in poorer condition than those contain- ing chemically refined rag and chemical wood fibers. Papers con- taining crude fibers were most frequently found in books printed

during the period 1875 to 1910, even valuable records being printed on papers of this type.

5. The uneven deterioration of different pages sometimes ob- served in old books is often due to the use of good and poor grades

of paper in the same book. VII. ACKNOWLEDGMENT

The assistance of W. L. Holt 18 and of the staff of the New York

Public Library, Coker College, Library of Congress, Princeton University Library, Columbia University Library, University of Utah

Library, University of Nevada Library, Seattle Public Library,

Portland (Oreg.) Public Library, University of Chattanooga

Library, University of Michigan Library, St. Louis Public Library,

Library of Iowa State College, University of Pennsylvania Library,

Oakland Free Library, University of Chicago Library, Library of Louisiana State University, and of Yale University Library is hereby gratefully acknowledged.

Washington, February 25, 1933.

18 Assistant research associate representing the National Research Council. O

i