though not as well illustrated, should find its place in the library of every modern and progressive surgeon.

THE INTERNATIONAL MEDICAL ANNUAL for 1905, and Year Book of Treatment and Practitioners Index. By many editors. Twenty-third year. Price $3.00. E. B. Treat & Co., publishers, 241-243 23rd st., New York.

We have each year been favored with this truly valuable work, and each year found that it presents distinct elements of improvement. This year its page is increased from a 12 mo. to an 8 vo. size, thus making the volume more convenient, allowing for more material, and permitting better display of illustrations.

The medical literature necessary to the medical student is represented by the text-book. This also is necessary for the practitioner, but there is also rendered essential the ephemeral literature represented by the medical journal, and, as a necessary concomitant, the year book. The work of the present one is especially able, its editors all being men of the highest reputation in the medical profession.

This work is essentially practical. It is divided into three portions. The first, devoted to therapeutic progress, occupies 102 pages. The second, devoted to new treatment, requires 510 pages. The third gives 8 pages on sanitary science. To this is added a short catalogue of the principal medical works published during the year 1904. Thus it will be seen that this is essentially a review of the two subjects of

therapeutics and treatment. The dictionary method is employed throughout, thus making it most convenient to the consultant.

HOW TO STUDY LITERATURE. A guide to the intensive study of literary masterpieces. By Benjamin A. Heydrick, A. B. (Harv.), Professor of English Literature, State Normal School, Millersville, Pa. Third edition, revised and enlarged. Price, 75 cents. Hinds, Noble & Eldredge, publishers, 31-35 West 15th st., New York City.

This little work will prove of value to those who, not having had the opportunity for competent personal instruction in the study of literature, nevertheless are unwilling to let that important part of general education and culture remain a lacking, or deficient element. Indeed, those whose school and college opportunities have not been wanting, will find in it helpful hints for further study and development. It recognizes the fact that education cannot be delivered to an individual as can a package of dry goods or groceries, but must be developed in the person through his own efforts, helped by example and friendly aid. The first portion consists of outlines and hints for the critical study of the various forms of literature. The second consists of a number of examples of the recognized highest types of such forms analyzed according to these outlines, and therefore will prove helpful to the student of literature. Added to these are appendices on figures of speech and versification and a list of

recommended reading, which latter serves as a most convenient and admirable guide.

THE PRACTICAL MEDICINE SERIES OF YEAR BOOKS. Comprising ten volumes of the Year's Progress in Medicine and Surgery. Issued monthly under the general editorial charge of Gustavus P. Head, M. D., Professor of Laryngology and Rhinology, Chicago Post-Graduate Medical School. Volume 9, Anatomy and Pathology. By W. A. Evans, M. S., M. D. Phy siology and Bacteriology. By Adolph Gehrmann, M. D. Dictionary of New Words. By William Healy, A. B. (Harv.), M. D. Price of the volume, $1.00; price of the series of 10 volumes, $5.50. The Year Book Publishers, 40 Dearborn street, Chicago, Ill.

A glance over the dictionary of new words serves to convey an idea as to the general activity in medical investigations. It forms a portion of the volume which can not fail to be valuable to the possessor.

There has been but little done in the fields of anatomy and physiology, as shown by the fact that the former department is covered by 12 pages, of which about three are given to illustrations, and the latter department by 17 pages. Much more activity has been shown in pathology and bacteriology. A very great deal of this is especially interesting to the general practitioner, because the material has been selected with special reference to the latter, and the descriptions are particularly clear. Perhaps that which will attract the most attention is the report of the recent investigations in the etiology of small-pox. Work, however, is represented in all of the several fields connected with the two subjects named, and technic has not been neglected.

FISCHER-INFANT FEEDING IN ITS RELATION TO HEALTH AND DISEASE. A modern book on all methods of feeding. For students, practitioners and nurses. By Louis Fischer, M. D., Visiting Physician to the Willard Parker and Riverside Hospitals, of New York City; attending physician to the children's service of the New York German Poliklinik; former instructor in diseases of children at the New York Post-Graduate Medical School and Hospital; Fellow of the New York Academy of Medicine, etc. Third edition, thoroughly revised and largely re-written. Containing 54 illustrations, with 24 charts and tables, mostly original. 357 pages, 534 x 834 inches. Neatly bound in extra cloth. Price, $1.50, net. F.A. Davis Company, publishers, 1914-16 Cherry street, Philadelphia, Pa.

We had the pleasure of favorably reviewing the first edition of the work after its appearance in 1901. The two revisions appearing since then have been considerably increased in contents, which has greatly added to the value. A chapter which has interested us especially is that on "Buttermilk Feeding", because we have found this of considerable value when a tuberculosis case did not take kindly to fresh milk, and we are exceedingly interested in its spread to the field of infant feeding.

Other new chapters of interest are those on "Milk Idiosyncrasies in Children,,' and on "Feeding of Children Afflicted with Cleft Palate", as well as that on "Scurvy". It is not saying too much when we add that the work can be

thoroughly recommended to the practitioner as a practical handbook with many features of practical value for the physician in his pediadric practice.

THE DOCTOR'S RECREATION SERIES. Charles Wells Moulton, general editor. Volume 2. The Doctor's Red Lamp. A book of short stories, concerning the doctor's daily life, selected by Charles Wells Moulton. 1904. The Saalfield Publishing Co., Chicago, Akron, O., New York.

This volume forms a worthy successor of the first volume of the series, which we had the pleasure of reviewing a few months ago. The stories selected are most of them by well recognized authors, and are worthy of preservation associated with each other as they are here. Humor, pathos, the physician's life in relation to the family, the patient and the community, are all touched upon by skillful hands. The physician will find that he, his family,. and his friends, can perfectly enjoy the work, and that the volume will make a most desirable addition to his library.

THE PHYSICIAN'S VISITING LIST FOR

.1905. Fifty-fourth year of its publication. For 25 patients per day or week, pencil pockets, etc. Price $1. P. Blakiston's Son and Co., Philadelphia.

A COMPEND OF THE DISEASES OF THE EYE AND REFRACTION. Including Treatment and Surgery. By George M. Gould, A. M., M. D., Editor of American Medicine, formerly Ophthalmologist to the Philadelphia Hospital, etc., and Walter Pyle, A. M., M. D., Assistant Surgeon to Wills Eye Hospital, Philadelphia, Associate Member of the American Ophthalmological Society, etc. Third edition, revised and corrected, with 109 illustrations, several of which are in colors. 1904. Price, $1.00, net. P. Blakiston's Son and Co., publishers, 1012 Walnut St., Philadelphia, Pa.

This quiz compend is already well known in its previous editions to the medical students throughout the coun try, and is an example of the best of quiz compends. In about 300 pages it presents very briefly the essentials of the medical and surgical diseases of the eye, and also the essentials of refraction, It is well illustrated.

VOL. XI.

No. 3

For a long time only three states of matter were recognized, the solid, the liquid, and the gaseous, but in the year 1816 that great philosopher, Michael Faraday, conceived of its existence in a fourth state, to which he gave the. name, "Radiant Matter", and he considered this state of matter to be as distinctly different from the gaseous as the gaseous is from the liquid, or the liquid from the solid.

A gas is believed to consist of an aggregation of separate and independent particles or molecules, each molecule being in constant motion, traveling or vibrating in a series of straight paths that are limited in extent by the density of the gas, or, in other words, by the distance between adjacent molecules.

The average distance which the gas molecules can travel before coming into collision with other molecules is called their mean free path, and it is evident that as a gas becomes more

and more attenuated the mean free path becomes larger and larger, its length being inversely proportional to the number of molecules which are contained in a given volume.

The process of exhaustion may be carried to a point where the mean free path of the molecules is so far extended that they can travel inside the containing vessel with comparatively few collisions, and when this condition exists Faraday's conception of "Radiant Matter" is fulfilled, and it is worth noting that this is also the proper degree of vacuum for the production of X-rays.

In 1879, Sir William Crookes delivered his memorable lecture on "Radiant Matter" before a meeting of the British Association at Sheffield, England. In this lecture he exhibited and described very highly exhausted tubes which were almost identical in outside form and internal construction with the X-ray tube of the present time.