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Milk fat will be deficient in A-vitamin if the animalbe not fed upon food containing it, such as green leaf,which is its ultimate source. The antiscorbutic valueof milk depends upon the animal’s food. The twobest foods are milk and green leaves. Milk suppliesgood protein and mineral matter, and vitamins iffrom properly fed animals. Green leaves are said tocontain good protein, and they are certainly rich invitamins. An ill-balanced diet will therefore be made

adequate by the inclusion of milk and green vegetables.

THE SOLDIER’S LOAD.

WHAT weight can a soldier carry and yet march andfight well ? Major N. V. Lothian deals with thisimportant question in the opening paper of theJournal of the Royal Army Medical Corps for October.The diseases ascribed to overloading have beenpulmonary emphysema, so-called soldier’s heart, and, Itentatively, trench nephritis. Some burden thesoldier must have : arms, armour, spade, clothing,food, to which he adds souvenirs ; together thesecannot weigh less than 40 lb., and men have carried 88.The problem has faced soldiers of all times. TheAthenian hoplite in battle carried 80 lb., but eachhad an attendant to carry his equipment to the field.Thus heavily weighted they were little mobile,consequently no sooner were they, as we may put it,standardised, than light infantry in considerablenumbers were added to all armies, and it was thesewho gave Philip of Macedon much of his success. Ifa soldier is well trained he can carry greater weightsmore easily, so the Romans specially trained theirrecruits to carry a load of 45 lb., while the legionarieseach month did three 20-mile route marches in heavymarching order, carrying about 50 lb. His pack hecarried on a forked stick, introduced into the serviceby Marius, and called after him, " Marius’s mule,"but much of his burden was, on service, borne for himby a servant (calo) or in carts, as may be seen on thecolumn of Trajan and elsewhere. Major Lothian’spaper is a valuable contribution to military science,worthy of the Army School of Hygiene from whichit comes, though it is defaced by careless printing ofLatin words.

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IRRADIATION OF LYMPHOID TISSUE.

As a result of clinical and experimental investiga-tions into the action of radium and X rays uponnormal and diseased lymphoid tissue carried out inthe Department of Cancer Research of the MontefioreHospital, New York, Dr. Isaac Levin1 concludes thatthe lymphocytes in the blood stream and lymphoidtissue generally throughout the body are extremelysensitive to these radiations. Dr. Levin is not alonein this opinion reports issued from various centres ofradium-therapy will generally be found to includedata showing the remarkable susceptibility of diseasedlymphoid tissue to radium. Lympho-sarcomata figureamong the tumours giving the highest percentage offavourable clinical results. Dr. Levin’s paper consistsfor the most part of short descriptions of clinicalcases illustrating his conclusions. Apart from theimmediate clinical results, his observations are

valuable as factors which must be taken into accountwhen any sort of generalisation is attempted on thissubject. More recent studies have shown that the ,,physiological response of the organism must in no casebe ignored when generalised exposures to radiationare given. Levin states that the rays do not actmerely as a local agent, but produce a generalisedeffect on the lymphoid system of the whole organism.The evidence for this statement is based upon obser-vations such as the following. In a case of lympho-sarcoma, examination showed a large diffuse massoccupying the whole of the right axilla and invadingthe pectoral muscles. In the left axilla was an enlargedfreely movable gland, the size of a hen’s egg. Theradium applications were made only at the rightaxilla, with complete disappearance of the mass there,

1 Journal of the American Medical Association, Sept. 17th.

as well as that in the other axilla ; this and othercases cited by the author are probably paralleled bythe experiences of radiologists elsewhere. Dr. Levincomments upon the hypothesis that specific enzymesare freed from the disintegrating lymphocytes, butoffers the timely reminder that hardly any workhas yet been done to clear up the problem. As thefield of utility of these radiations widens in medicine,the necessity for investigations becomes increasinglyurgent, for the feeling of insecurity of any practicebased upon empiricism increases with the dimensionsof the superstructure. ____

THE EFFECTS OF PROLONGED DEPRIVATIONOF SLEEP.

Prof. G. W. Crile, in his recent studies on exhaustion,has extended his observations on this subject, andhas determined the effects in rabbits of prolongeddeprivation of sleep-96-118 hours. Marked changesare thereby produced in the cells of Purkinje in thecerebellum ; in the first stage there is an increase ofthe chromatin material-both in its diffuse and par-ticulate form, in the plasma and size of the nucleus ; gthe cells contain an average amount of chromatin,but changes manifest themselves in the dendrites.Then the chromatin diminishes, and its remainscollect around the periphery of the cell and nucleus.In the next stage the chromatin completely disappears,the cytoplasm showing disintegrative changes, andvacuolisation ; somewhat similar changes affect thenucleus, and in extreme cases there seems to bedeath and complete disintegration of the cells. It issuggested that neither man nor animal can survive theloss of 15 per cent. of the brain cells. In eight experi-ments, six animals showed more or less pronouncedchanges in the liver, especially at the periphery ofthe lobules. The nuclei lay excentrically and weredeformed, the granules diminished or absent, vacuoleswere present and the cell as a whole materiallychanged, including the disappearance of its glycogen.In five cases out of six the medulla of the adrenalglands was not affected, while the cortex in six outof eight cases showed changes and disintegration afterloss of the nuclei. No marked changes were noted inthe thyroid, pancreas, kidneys, spleen, stomach, orintestines. By inducing sleep at the end of a sleeplessperiod, and by the action of different agents, the authorendeavoured to mitigate the effects and restore theactivities of the injured cells. Sleep and nitrousoxide have a marked recuperative effect, except incases where the disintegration of the brain cells hasproceeded too far. As experimental poisoning byacids produces similar changes in the cells of thebrain, liver and kidney, the pH of the blood wasdetermined, but it was found that sleeplessness pro-duced no marked change, the pH being nearly thesame during the sleeping as in the waking condition.

THE PREVENTION OF DIPHTHERIA.

LAST winter the incidence of diphtheria was high,the mortality correspondingly high, and the numberof cases notified so far this.autumn points to a severewinter epidemic. In America the mortality fromdiphtheria is apparently heavier than it is in England,and the public health authorities there are institutinga campaign to stamp out, the disease on the principlethat since its prevention and cure are known, the diseaseshould be eradicable. The method of the campaignis to confer active immunity on all children betweenthe ages of 6 months and 6 years by the injectionof three doses of toxin-antitoxin, thereby renderingthe children insusceptible of infection for several yearsor maybe for life. This is especially applicable toyoung children, as the mortality from diphtheria aswell as the incidence of the disease is vastly greaterin the younger age periods. Children at birth arefound by means of the Schick reaction to have anatural immunity to diphtheria, which fades away

1 Archives of Surgery, vol. ii., 1921.