It is a more powerful explosive than T.N.T. It was proposed for use as a booster, but was little used, as the process of manufacture and conditions for use were not satisfactorily perfected by the time the Armistice of November 11, 1918, was declared. Its discovery, therefore, was in no sense a decisive factor in the defeat of Germany.

It will be observed that T.N.A., therefore, was discovered by an English chemist, ten years before the war broke out, was patented in England, the United States and Germany, four years before the war began, and, therefore, was well known to German chemists.

On June 5, 1923, I wrote to Dr. Riley, enclosing a copy of Professor Munroe's letter. I concluded my letter as follows:

I call upon you now, formally, hereafter to eliminate the two paragraphs on page 16, for it is an absolutely wrong statement, as you can see by looking up the patents, if you wish to.

For about two years this pamphlet was sold without any alteration of the text. Of late Dr. Riley has added a note on the margin of this paragraph recounting the discovery of T.N.A. by the two young American chemists, as follows: "This illustration, given me by a chemist, is disputed." He is attempting to "save his face" by perversion of the facts. Professor Munroe did not "dispute" this illustration. His letter, above quoted, showed it to be false.

To my limited knowledge the chemical procedure, as described by Dr. Riley, is unintelligible. Professor Munroe wrote that it was "arrant nonsense."

PHILADELPHIA, PA.

W. W. KEEN

THE PROPAGATION OF APPLE VARIETIES

BY CUTTINGS

IN the Journal of Heredity, September, 1925, attention has been called to the occurrence of burrknots, which contain root rudiments, on the stems of certain varieties of apple trees, and to the fact that these root rudiments can be readily forced into growth by maintaining damp moss around the stems. It was suggested that probably such material could also be used as detached cuttings in the vegetative propagation of certain varieties of apples. The writer is now able to report that the varieties Buckskin, Springdale, Northern Spy and Buckingham (the only varieties used in the first test) have been propagated by detached cuttings. A commercially satisfactory percentage (above 80 per cent.) of rooted cuttings was obtained. The material used was of pencil size or

a little larger and was of the fruit-spur type, being .three to five years old. Root rudiments were more or less evident on each cutting at the time it was taken from the tree. The material was cut July 15 from bearing trees in the orchard of the Arlington Experiment Farm, near Washington, D. C. The cuttings were placed in sand in one of the Washington greenhouses, a bench without bottom heat being used. When lifted on August 19, almost every one showed roots from one fourth to four inches in length, although very little callus was observed. There was some evidence to indicate that the presence of functioning leaves was advantageous to root development, as was mentioned by Van Der Lek1 for willow, poplar and grape cuttings.

From these results it seems that the propagation of apple varieties by hardwood cuttings depends at least in some cases upon the use of material in which root rudiments are already present. It is hoped that physiological studies, now in progress, will throw some light on the question of what are the conditions that bring about the initiation of such root rudiments. The writer will be glad to learn of observations by other workers on the relation of burr-knots and previously formed root rudiments to the rooting of cuttings.

BUREAU OF PLANT INDUSTRY, WASHINGTON, D. C.

CHARLES F. SWINGLE

THE MACKEREL AND PLANKTONIC
ORGANISMS

THE life history of the true mackerels belonging to that great family of Scombridae is full of romance and takes us back to the days of Horace and Pliny. The ancients considered the mackerel a fish of mystery and down to the present time the migratory habits of this great food fish have constituted a problem not easily solved. Lacepede, the French naturalist, in 1798 came to the conclusion that mackerel pass the winter in the Arctic region, where hibernation takes place with their heads buried in the mud.

Badham, writing in 1854, says, "The migrations of mackerel have given rise to wide excursions of the imagination and to much ingenious speculations." The investigations made at Port Erin on planktonic life by Johnstone, Scott, Chadwick and Herdman will prove invaluable in finding the missing link to the life history of the mackerel family.

During the past few years Professor Herdman has

1 Van Der Lek, H. A. A., "Over de wortelvorming van houtige stekken," Medeelingen van de landbouwhoogeschool te Wageningen (Nederland), Vol. 28, No. 1, 1925.

made an examination of ten thousand samples of plankton relative to growth, reproduction and movements of planktonic organisms. This investigation goes to show that temperature and salinity are a great factor in the rise and fall of planktonic life. Since 1910 the mackerel catches on the Atlantic coast have declined to an alarming extent.

Some of the English scientists have advanced the idea that the mackerel are leaving America and migrating to the European coast. If this is a fact and taking into consideration that mackerel are plankton feeders the solution seems to be centered around the study of planktonic organisms.

The investigation of the seasonal distribution of plankton in the Woods Hole region by Dr. Charles J. Fish, Bureau of Fisheries, will in all probability pave the way towards surveying the Atlantic coast.

No doubt the tagging of mackerel will show appreciable results. But unfortunately many uncontrollable factors enter into the above experiments, such as hyperglycemia due to handling the fish and being exposed to the air, thus causing them to fall easy prey to their enemies after being returned to the water.

U.S. BUREAU OF FISHERIES, WOODS HOLE, Mass.

RALPH C. JACKSON

ABSTRACTING OLD BOTANICAL WORKS AND MANUSCRIPTS

THE value of a complete abstract journal can not be overestimated; we all recognize the great importance of periodicals, such as Botanical Abstracts, Bo tanisches Centralblatt, Chemical Abstracts and a number of similar papers in other fields of learning.

These publications, however, are of relatively recent origin. For example, Just's Botanische Jahresbericht was founded by Just in 1873. Botanisches Centralblatt was started in 1880. Previous to this time a wealth of important work had been published: some of it can be found in a number of well-known serials. Some of them are still being published, but the earlier issues are not easily obtainable, except in some of the large institutions of the Old and New World. We need mention only Curtis's Botanical Magazine (1786), Botanische Zeitung (1843), Linnaea (1826), La Belgique Horticole (1851), Transactions and Proceedings of the Botanical Society of Edinburgh (1843), Transactions of the Royal Society (1663), Flore des Serres et des Jardins de l'Europe (1845) and a number of others.

I have spent considerable time in a number of libraries like those of the British Museum, of Kew Gardens, of the University of Amster

dam, of the University of Berlin and others, studying works on plants and on their economical aspects published in earlier centuries. One is surprised by the fine talent of these observers and workers of times long past, men who were heretofore unknown to us. From the sixteenth until the beginning of the last century men like Malpighi, Grew, Swammerdam, van Leeuwenhoek, Camerarius, Linné, Koelreuter or Sprengel have given us an indelible impression of their achievements, but there are others whose work has been forgotten, and no one can estimate the advantage it will be to science and history to have their work revived. If we consider only the work of an investigator of later date, namely, that of Gregor Mendel, one will realize the importance of this task of abstracting.

There are international catalogues besides those of libraries which will facilitate this work considerably. Also publications like Seguier's "Bibliotheca Botanica," 1740; Wikström's "Litteraturae Botanica in Suecia," 1831; Krüger's "Bibliographia Botanica," 1841, and treatises on the history of botany during certain periods which will contribute very much toward making the task of finding originals easier.

In many libraries there are unknown manuscripts, which are not published and probably never will be published, but which are of enormous value. They may contain views or observations which were not ripe for these days, and therefore were not fully comprehended by the learned world of that time. systematic search, a perseverance and last but not least a love for one's profession will ensure the completion of this work, which will not only be of great historical value but also to science itself.

ORLANDO, FLORIDA

J. C. TH. UPHOF

SCIENTIFIC BOOKS

Entwicklung und Bibliographie der PathologischAnatomischen Abbildùng. By EDGAR GOLDSCHMID. Leipsig, Karl W. Hiersemann, 1925, 301 pp., 44 pl. 4°. Price 150 marks.

THIS is the first serious attempt to grapple with a theme of some moment to medicine, namely, the history of pathology. Pathology, as a generic term, connotes and comprises everything relating to the essential nature of disease. In ordinary usage, however, it denotes the changes in structure and function produced by disease and thus includes both the "anatomical idea" of Virchow and what Allbutt styled "altered physiology," i.e., the facial appearance and physical habitus of different diseases, as well as in paralytic deformities and other derangements of function. The

plates in the present volume cover changes in the external configuration of the face and body (semeiology) as well as pathological changes in structures beneath the skin. It is plain that this phase of the history of pathology is largely the history of its delineation by skilled artists. The author, a Frankfurt professor and prosecutor in the Senckenburg Pathological Institute, has therefore followed the ground-plan of Choulant's famous "History of Anatomical Illustration" (1852). If his adherence to the Choulant tradition seems a bit too formal at whiles, it is to be remembered that his model is one of the greater classics of medicine, a work of infallible accuracy, representing a lifetime of patient research. His book begins with a sketch of the history of pathological illustration, including the technical processes of reproduction. This is followed by a brief bibliography of sourcebooks, after which the author launches bravely into a complete reasoned bibliography of books containing pathological pictures, arranged in five chronological periods. There follow valuable and accurate indices of authors, artists, publishers and books (under authors' names), a subject-index of the diseases and parts of the body illustrated in the different atlases and an index of the forty-four plates, twenty-eight of which are handsomely colored.

The prehistory of the subject comprises accidental figuration of pathological formations on antique vases, stelae, papyri, frescoes, old MSS., primitive pottery, ex voto tablets and the like. Between this phase and the period of conscious or intentional illustration of pathology come the chance figurations on fugitive sheets, in non-medical books, oil paintings, sculpture of the post-antique period and so on. Examples of the early phases, as presented in the plates, are a votive tablet from Athens representing varicose veins, a bit of Huaco sculpture showing facial paralysis, terra-cotta figurations of the facies of disease from Asia Minor, Albert Durer's colored print of syphilis, Ghirlandajo's rhinophyma and a painting of Simon Vouët's, showing suppurative osteomyelitis. The first period of illustration with didactic intention begins with the start made in first-class anatomical illustration by Leonardo da Vinci and Vesalius and goes down to the time of the great surgeon-anatomists of the 18th century (1517-1733). It is the period of wood- and copper-plate engraving and etching, illustrated in the volume by cuts from Bonetus (1686), Valentini (1715) and Heister (1715). The second period, from Cheselden to Soemmering (1733-92), is the period of the surgeon anatomists who produced great atlases in copper and steel-engraving. The third period, from Sandifort to Cruveilhier (1793-1829), marks the rapid victory of colored lithography over colored copper-plates, splendidly exemplified in the pathologi

cal reports of Richard Bright (1827-31). The fourth period (1830-60) finds its high spots in the atlases of Cruveilhier (1829-42), Carswell (1838), Lebert (pathological histology, 1845), Danielssen and Boeck on leprosy (1848), Auvert (1851), in the work of the dermatologists and in Virchow's Archiv (1847-1925). The fifth period runs from 1860 to the recent developments of chromolithography, photography and the low-priced hand-atlases. The colored plates illustrating these periods are of superlative excellence, particularly those from Cruveilhier, Lebert, Auvert and the dermatological atlases of Alibert (1817-28), Bateman (1830) and Rayer (1839). One misses, it is true, the Venus of Willendorf, the earliest known bit of prehistoric sculpture (showing the endocrine phase of obesity), the achondroplasic dwarf figurines of Egypt, collected by Charcot, the pathological plates of Richard Bright (1827), Corrigan's superb engraving of aortic insufficiency (1832), the facies of Addison's disease (1855) and the wonderful iconography of nervous diseases made under the inspiration and guidance of Charcot. The Nouvelle Iconographie de la Salpétrière is, in fact, treated with scant courtesy. Our author does not seem to realize that it consists of twenty-eight stout volumes (1888-1918) containing the most valuable illustrations of the pathology and semeiThese picology of nervous diseases in existence. tures show not only the facies and habitus in typical cases, but, in accordance with Charcot's teaching, carefully selected atypical or incipient cases, so that a person with a tendency to acromegaly or exophthalmic goiter might be recognized (say) in a street-car. The excellent Revue photographique des hôpitaux de Paris (1869-72) is also omitted. These, however, are slips which it will be easy to correct in a subsequent edition. The book is obviously a vade mecum for all medical librarians and will find its way into the collections of professional pathologists who care for their subject. The format is, if anything, too massive and sumptuous. A later edition in smaller size, and with a more definite choice of pictures, would be a valuable acquisition for the active practitioner and surgeon.

ARMY MEDICAL LIBRARY, WASHINGTON, D. C.

NOTES

F. H. GARRISON

THE State Board of Fisheries and Game of Connecticut has just issued "A report of investigations concerning shad in the rivers of Connecticut," by P. N. Mitchell and staff (1925, 63 pages, illustrated) which contains detailed analytical data such as is necessary for intelligent conservation of a given species of fish. Embryology, food, growth, enemies and para

sites of the shad are discussed, as also the environment. A considerable amount of new information is here contained, and we may mention particularly the contribution to the fascinating science (or art) of reading age and life history from the structure of fish scales, by N. Borodin. It seems that for almost every species of fish this presents a separate problem. In the shad scale, so-called "annuli" are difficult to find, but distinct transverse grooves, running across the annuli, #! two for each year, are readily made out. Dr. Borodin's results are corroborated in a study of otoliths by R. L. Barney.-J. T. NICHOLS.

A MONOGRAPH, "The Termites of Kartabo, Bartica District, British Guiana" has been lately issued by the department of tropical research of the New York Zoological Society. Dr. Alfred E. Emerson, associate professor of zoology at the University of Pittsburgh and for several years associated with the University Zoological Station at Kartabo, British Guiana, is the author. Seventy-eight species, fifty-one of them discovered by Dr. Emerson, are classified in the volume.-LORENZ G. WALTERS.

IN 1902 the Coast and Geodetic Survey published "Principal Facts of the Earth's Magnetism," by L. A. Bauer, then inspector of magnetic work. This covered the early history of the development of knowledge in regard to the earth's magnetism and gave an appraisal of the knowledge of the subject at the time the publication was issued. A new publication "The Earth's Magnetism," by D. L. Hazard, assistant chief of the division of terrestrial magnetism and seismology, U. S. Coast and Geodetic Survey, replaces the earlier one and it covers not only the early history, but also that of the important period since 1902, during which so much advancement has been made in our knowledge of the subject. It is a fact that this period of intensive world-wide study has made very great progress. At the same time it must be recognized that the final solution of the problems is still very far in the future. The outstanding feature of the first quarter of the twentieth century was the extension by the Department of Terrestrial Magnetism of the Carnegie Institution of Washington of magnetic surveys of all parts of the earth not covered by national governments, and to the high seas. Also the precise work done by many governments, especially that of the United States through the Coast and Geodetic Survey. It appears that in every branch of scientific investigation which must be expected to continue for a long period, appraisal from time to time of the progress that has been made is almost as essential as the actual carrying on of the work.-R. L. FARIS.

SPECIAL ARTICLES

X-RAY DIFFRACTION PATTERNS FROM PLANT MATERIALS

DURING the past three or four years the writer has been making many X-ray diffraction patterns of the materials of plants which are normally thought of as solid substances, such as starch grains, cell-walls, both lignified and non-lignified, and those of hemicelluloses. These materials are very probably built up by additions of layer upon layer at the interfacé between the substance and the living protoplasm, and for that reason they would be expected to have a certain regularity in their structure. The fact that diffraction patterns are obtained from them is evidence that there is undoubtedly a degree of regularity in the structure, which could only be surmised heretofore. Diffraction lines have been obtained from many plant materials, among which are bast fibers of ramie and hemp; hairs of cotton; tracheids of spruce; starch grains of potato, corn, wheat, cassava and arrow-root; and the sclerenchyma cells from the seeds of Phytelephas and of another palm, Erythea.

3

In the table only a few of the diffraction lines obtained are given, and they include only the wider interplanar spacings for a few representative substances. More complete studies are given elsewhere,3 or will appear in the literature at an early date. Since the earlier publications on starch, refinement in the apparatus and a better technique have resulted in the resolution of several lines and in their more accurate measurement. The figures in the table, therefore, will not check exactly with those in the paper to which reference was made. A revision of the earlier work is, of course, necessary, but so far 1 Hull, A. W., Phys. Review, X, 661-696, 1917; and XVII, 571, 1921.

2 Bragg and Bragg, "X-Rays and Crystal Structure,' London, 1924.

3 Sponsler, O. L., Amer. Jour. Bot., IX, 471, 1922, and Jour. Gen. Physiol., V, 757–776, 1923.

The significance of the figures given in the table becomes more evident when we recall the chemical composition of the substances and the way in which diffraction lines are produced. For details of the latter we must refer to the literature already cited. In general, however, we may think of the lines as being produced by "reflection" from planes or layers of atoms, and as the result of reflection from hundreds or thousands of those planes very uniformly spaced. The substances are all carbohydrates of the hexose type. The atoms which produce the reflection, therefore, are those of carbon and oxygen. Hydrogen has a negligible reflecting power, and the amount of other elements which might occur is too small to produce diffraction lines.

In the table it will be noticed that the dimensions of the spacings are comparatively uniform for the different substances. The greatest interplanar spacing is about the same in each; that is, in the neighborhood of 6 A.U. All of them are greater than 3 A. U. Since the diameters of oxygen and carbon atoms are about 1.5 A.U. or less, it seems fairly certain that the units which make up the lattice structure of these materials are composed of groups of

atoms.

5

It is not, of course, a safe procedure to predict the size of these structural unit groups until the lattice is carefully worked out, but attention should be directed to what seems to be at least a peculiar coincidence. The volume of a C.H100, group of atoms as it occurs, presumably, in the materials is about equal to the volume of an elementary cell whose dimensions are 6 x 5.5 x 5 A.U. Approximately the same values are present in each column of the table. The C group seems to be the structural unit in starch grains and in plant fibers, and from the data

4 Ibid.

s Ibid.

The data on plant fibers will soon be submitted for publication.

so far presented it would not be surprising if that group kept its identity throughout all these materials.

We may feel fairly certain of this much-that in the plant parts with which we have been working units of structure which approach in size that of a C. carbohydrate group occur in a very uniform arrangement; that is, they are not laid down in a haphazard manner. On the contrary, each unit is fitted more or less neatly in place so that a definite lattice structure is formed.

UNIVERSITY OF CALIFORNIA,
SOUTHERN BRANCH,

LOS ANGELES, CALIFORNIA

O. L. SPONSLER

SUCTION FORCE OF SOILS: A NOTE ON THE
APPLICATION OF THIS PRINCIPLE

IN THE STUDY OF THE SOIL-
PLANT SYSTEM1

It was pointed out how the principle of the suction force of a soil may be utilized for the estimation of the soil colloids. The suction force is measured with the aid of a mercury manometer attached to a porous clay candle which is filled with water and inserted in the soil. The capillary and molecular forces exert a pull on the water producing a negative pressure in the clay candle which is registered on the manometer. The greater the amount of colloids in the soil the greater the suction force. The ratio from the same soil multiplied by 100 gives the percentage of colloids in the soil. The figures in the following table will suffice to illustrate the relationship between the amount of colloids present and the suction force. The various types of the same soil series contain various amounts of clay and apparently the suction force follows the clay content.

Clay

Percentage

4.15

4.68

7.11

19.09

21.82

Suction force: rise of mercury column on manometer

The figures on the clay content are taken from the

1 Paper No. 248 of the Journal Series, New Jersey Agricultural Experiment Stations, Department of Soil Chemistry and Bacteriology.

2 Joffe, J. S., and McLean, H. C., 1925, "Colloidal behavior of soils and soil fertility. I. Suction force of soils as an index of the colloid content of soils." To appear soon in Soil Sci., v. 20, 1925.