mild alkaline solution seems to be entirely satisfactory in preventing a spread of the existing condition.

It is of the utmost importance that the patient should be directed to use his own towel and soap during the existing condition, and should as well use his own bedclothing, which should be thoroughly scalded after the patient is entirely cured.

Regarding the question of syphilitic patients who have apparent cutaneous manifestations, they should certainly be most. thoroughly informed as to their existing condition; they should be told to use their own eating and drinking utensils; they should be cautioned about using public fountains for drinking purposes; they should be cautioned about going into public places to eat or to be shaved, or in public baths, or anywhere at all in which they would come in contact with the public at large.

It is just as important for the public to be cautioned regarding the existence of such conditions; they should be instructed not to drink from public cups which are attached to drinking fountains; those who patronize the cheaper restaurants should be cautioned about drinking from cups or glasses which have cracked edges because of the fact of the danger of disease germs lurking in these crevices which are not properly cleansed or sterilized.

Another factor in the prevention of spread of skin diseases in public places is the use of liquid soap, which is now installed in nearly all modern public places.

Many barber shops which are not modern in their technic are the lurking places of many skin diseases which are transmitted to many an innocent person. A number of these shops are responsible for the transmission of such diseases as syphilis, barber's itch or the true ring-worm, sycosis vulgaris, common baldness, furunculosis, impetigo contagiosa, etc. Many of the cheaper barber shops have the habit of using hot towels on a patron which are repeated from one patron to another. The barber, by the use of the same comb and brush, disseminates the germs which are responsible for baldness.

The advice, therefore, to the general public should be that those who patronize the barber shop should have their own brush and comb, which should occasionally be sterilized. There are, however, many of the more modern of the barber shops. today which have a sterilizing apparatus of their own in which towels, combs, brushes and shaving utensils are sterilized in the presence of the patron, an attendant standing beside the barber handling the sterilized towels, etc., upon a sterilized tray.

A remedy for the existing evils in barber shops should be the passage of laws regulating the fitness of barbers to follow

their trade and laws regulating the sanitary conditions of their emporiums. Such laws, according to my present knowledge, now exist in Wisconsin, Michigan, Kentucky, Missouri, Minnesota, Connecticut and Washington. In New York, New Jersey and California, if I am not misinformed, such laws have not been upheld.

It appears to me that the best solution of the problem would be that the local boards of health should have the responsibility in charge of the sanitation of the barber shops, and should see to it that all barbers have a general understanding of the nature and effects of contagious skin diseases and of the proper laws and rules regarding sterilization and sanitation. Thirty-seven South Nineteenth Street.

LEUKÆMIA*

By HELMUTH ULRICH, M.D., Boston, Mass.

The literal English equivalent of leukæmia is white blood. If the number of leukocytes in the blood is very high, then this fluid actually assumes a more or less whitish, or, rather, grayishred color. But the term leukæmia has come to mean an increase in leukocytes, and is applied particularly to the two types of that disease in which this increase, correctly designated leukocythæmia, or leukocytosis, may reach its greatest heights.

At the outset, it is imperative to emphasize the difference between the symptom leukæmia and the disease leukæmia. Thus, although the symptom, that is, an increase in the number of leukocytes in the blood, may be and usually is very marked in the disease, yet the disease may exist without the symptom; and, conversely, an increase in leukocytes by no means warrants the diagnosis of leukæmia, the disease. In fact, a host of ailments, most of which are much more common than the disease leukæmia, include an increased leukocyte count in their symptomatology.

The foregoing makes apparent the advisability of designating the symptom with the more appropriate appellation leukocytosis and reserving the term leukæmia for the disease. It is in this sense that these two terms shall be used here.

To avoid confusion, but at the same time at the risk of adding to it, some of the many synonyms applied to the disease may be given.

Synonyms.

mentioned. Lympholeukæmia or leuko

Leukocythæmia has already been cythæmia, lymphæmia and lymphatic cythæmia are used when the excess of cells is made

*Read before the Alethean Club of Boston, November, 1915.

lymphocytes; and, similarly, myelocythæmia, myelæmia and myelogenous, myeloid, splenomedullary, or splenic leukæmia or leukocythæmia, have been applied when cells of the myelocyte series predominate. Leukanæmia has been used alone or modified by one of the above adjectives; chloroleukæmia and chloroma have reference to those cases that show greenish nodules, especially about the head. Pseudo-leukæmia is, perhaps, more frequently but certainly not less incorrectly applied to Hodgkin's disease than to leukæmia. When used in connection with the latter, the cases with only slight leukocytosis or even normal white counts are meant.

As already indicated, leukæmia occurs in two general forms, the lymphatic and the myelogenous. Both of these types may be either acute or chronic, the order of frequency in which they appear being: Acute lymphatic, chronic myelogenous, chronic lymphatic, and acute myelogenous. The last named is rare.

Gulland and Goodall mention mixed forms, but in all probability faulty staining methods, as a result of which some of the earlier forms of the myelocyte series (leukoblasts, lymphoidocytes) were, no doubt, classed wrongly as lymphocytes, must be held responsible for such a conception. In a somewhat different sense, however, I venture to suggest that, perhaps, all cases are mixed cases. That is to say, in all cases there is, probably, simultaneous, but very rarely equal involvement of lymphoand myelo-poietic tissue. Acute cases, especially, are prone, and would be expected to show hæmatological evidence of such general involvement.

Pathology.

The chief anatomical changes are blood formation and blood destruction

found in the organs of - the bone marrow, the

lymph and hæmolymph nodes, and the spleen.

Yellow marrow is replaced to a great extent by red marrow. It is largely made up of the type of cell that predominates in the blood, that is, lymphocytes and their ancestors in lymphatic leukæmia, and cells of the myelocyte series in the myelogenous form of the disease..

The lymphnodes are usually enlarged, particularly in the lymphatic form. The size of the nodes and the number affected depends in great measure upon the chronicity of the disease. Thus, in chronic lymphatic leukæmia almost every node in the body may show enlargement. Histologically, the enlarged nodes show invasion with the same kind of cells found in the blood. In lymphatic leukæmia, especially, there is so great an engorgement with lymphocytes that the normal differentiation into cortex, with its germ centres, and medulla entirely disappears.

In

The spleen is enlarged, specially in the chronic cases. chronic myelogenous leukæmia, the spleen may reach an enor mous size, extending below the pubis and beyond the median line to the right (Fig. 1). Microscopically, the chief feature

is extensive invasion with cells corresponding to those in the blood. Evidence of blood destruction in the form of pigment that gives the Berlin blue reaction for iron is usually present.

Just as in the hæmatopoietic and allied organs just described, so in most other structures the chief pathological change is an infiltration with the predominating white blood cells, usually with some consequent enlargement. Almost any organ in the body may be affected, usually the liver, the gastrointestinal tract, the muscles including the heart, and the kidneys. The Blood.

It is practically always easy to diagnose leukæmia from a blood examination, and usually this is the only way it can be diagnosed. An occasional case with a normal leukocyte count may escape detection, but with our present excellent staining methods this ought to be a rare occurrence, because the number of leukocytes is less important than the presence of youthful forms.

The red cells are affected secondarily and usually not to a very great degree. There are always signs. of some anæmia,at first very slight, but increasing as the disease progresses, until,

in advanced cases, it may take on a pernicious type. This finds expression in the presence of many unusually large red cells, both nucleated (megaloblasts) and not nucleated (megalocytes), and of many very deeply staining hyperchromic ones. This hypercytochromia has for its cause an abnormally large amount of hæmoglobin in the cell, which is also responsible for the high color index characteristic of pernicious anæmia.

Ordinarily, however, the anæmia is of the simple secondary type, with a low color index (relatively greater diminution of hæmoglobin than of red cells), moderate distortion (poikilocytosis), inequality in size (anisocytosis), pallor (hypocytochromia) and abnormal staining quality (polychromasia) of a portion of the erythrocytes. The severity of the last four phenomena depends largely upon the stage and type of the disease, and any of them may be practically absent. The number of red cells and the percentage of hæmoglobin, too, are variable. and range from nearly normal to 1,000,000 or less and 15% or less, respectively. Nucleated red cells may or may not be numerous and in this type of anæmia are usually normoblasts, although later megaloblasts also appear.

The most interesting and important changes, and those that are characteristic of the disease, affect the white cells. It is commonly supposed that a high leukocyte count is essential for a diagnosis of leukæmia. That is an erroneous conception. High counts, to be sure, are the rule, and only exceptionally may an acute case, or possibly a chronic one during a remission, show a normal or only slightly increased count. The myelogenous form shows, on the whole, a larger number of cells than the lymphatic, e.g., an average of 300,000 against one of about 125,000. The acute cases have much lower average and, sometimes, even normal counts.

Examination of stained films practically always settles the diagnosis, even when the total leukocyte count is low. In the presence of an exceedingly large number of white cells, it is often difficult to spread a proper blood smear. The slides to be used must be properly cleansed, and usually considerable dexterity and experience is required to spread the film evenly. The choice of a staining method, too, is of prime importance, and sometimes more than one should be used to bring out various structural details. By far the best method in nearly every way is the one devised by Pappenheim, combining the merits and avoiding most of the defects of Giemsa's stain and May-Grunwald's solution. Wright's modification of Leishman's stain also is good and approaches Pappenheim's method in its results. The widely used Jenner's stain still has a place, perhaps, as a preliminary routine method where an unusually large number of slides are