A CONTRIBUTION TO THE STUDY OF THE QUESTION OF PIGMENT FORMATION IN THE SKIN OF THE NEGRO.

Dr. Morrison, Baltimore (in Monatshft. f. P. D., Vol. IX, No. 11). This interesting paper was read at the Paris Congress in September last, and bears on the question as to whether the negro foetus, or newly born infant's skin, contains more pigment than that of the white. The author insists that this is the case, and gives clinical and microscopical facts from personal observation to prove his case. It has been generally accepted hitherto, that the pigment deposit was an after-occurence, as, of course, it is in a major degree; this last fact is naturally accepted by the writer of the paper.

ON SEBORRHEAL ECZEMA AND ITS RELATION TO OTHER SKIN ANOMALIES.

Dr. H. G. Brooke, Manchester, Eng. (Monatshft. f. P. D., Vol. IX, Part 12). The doctor in this compliments Unna highly for his studies concerning the above-named class of skin affections, and points out his reasons for his belief in its etiological connections with various diathetic conditions, chief among which may be named the lithic acid diathesis.

RESULTS OF BACTERIOLOGICAL EXAMINATIONS AND STUDIES, IN THE CHRYSAROBIN TREATMENT OF TRICHOPHYTORIS. (HERPES TONSURANS).

Dr. V. Sehlen, Hamburg (Monatshsft f. P. D., Vol. IX, Part 12, p. 547), gives the result of his experiences of the cultivation of the trichophyton, and his experiments with parasiticides, for cryptogamic growths. Recommends chrysarobin greatly from this standpoint.

ON THE LICHEN QUESTION.

Prof. M. Kaposi, Vienna (Archiv. f. Derm. and Syph., 1889, Part 5, p. 743). In this article, Kaposi defends the Vienna dogma of the identity of lichen ruber and lichen planus, and does it with his usual energy. This has been before referred to in these reviews, and it will be remembered that he is totally at variance with almost all American dermatologists, and many of those of his own continent.

ON IMPETIGO HERPETIFORMIS.

Dr. Theodor du Mesnil and Herr Karl Marx (Archiv. f. Derm. u. Syph., 1889, Heft 5, p. 657). The authors insist on the absolute entity of this disease, contrary to the opinions of many, and claim the conversion of Duhring, hitherto one of its most strenuous opponents, he having classed it as of the order of "Dermatitis Herpetiformis." A somewhat interesting case bearing on the subject is given by Sherwell in the Journal of Cutaneous and Genito-Urinary Diseases for December, 1889.

ON TATTOOED MARKS.

M. Variot (in Annales de Derm. et Syph., Oct. 25, 1889, p. 847). The author gives a method which he thinks practical for removal, or

He first applies a saturThis he pricks into skin in

at least partial obliteration of such marks. ated solution of tannic acid to the part. same way as that in which the original coloring matter is introduced; he follows this by rubbing the solid stick of nitrate of silver over the surface. He claims to have seen good results follow from the subsequent inflammatory changes and slight consequent ulceration.

BACTERIOLOGY.

BY B. MEADE BOLTON, M. D.,

Director of the Department of Bacteriology, Hoagland Laboratory, Brooklyn.

THE PHYSICAL EFFECT OF SEDIMENT UPON THE MICRO-ORGANISMS
CONTAINED IN WATER,

Bruno Krüger (Zeitschrift f. Hygiene, 7 Bd., 1 Heft). In a few preliminary experiments K. substantiates the observations of Cramer, Bolton, and others, that at ordinary temperatures the bacteria greatly increase in water. This increase is not indefinite, but finally gives way to a rapid decrease. K. investigates the causes of the latter. He concludes that the bacteria disappear from water in nature on account: 1. Of exhaustion of nutrition.

2. Of freezing and thawing.

3. Of possibly the influence of direct sunlight.

4. Of sedimentation. This he regards as the most potent. Sedimentation of the bacteria certainly takes place in many cases in water which is undisturbed; and the dead organic and inorganic particles of matter tend to carry the bacteria down with them when they settle. The latter process is greatly assisted by the addition of various heavy powdered substances to the water.

In the first place, chemically indifferent substances were tried, viz.: dry powdered clay, calcium carbonate (whiting), silicious deposits. from a water-bed, aluminium oxide, pulverized slate, wood charcoal, coke, and sand. Coke and sand are specifically much heavier than the others, and the effect upon the micro-organisms less apparent. An addition of .5 grms. and 2 grms. to the litre in two separate experiments reduced the number of bacteria in the upper and middle portions of water one-half. Addition of 2 grms. of sand had the same effect, but .5 grms. of sand had no effect. It was not found necessary to make observations continued for great lengths of time, as it was found that these substances had settled in from thirty minutes to three hours. On the other hand, the silicious guhr, added in the proportion of .5 grms. per litre, decreased the number of organisms contained in the upper and middle portions of water fourteenfold in twenty hours, and

an addition of 2 grms. p. 1., fiftyfold in the same length of time. The other substances behaved similarly to the guhr.

The substances act in two ways: 1st, by mechanically pressing down the organisms which lie below; 2d, by attracting the organisms. Consequently, substances which remain longest in suspension have the greatest effect. The effect is more apparent in the middle and lower portions of the water than in the upper. This would naturally be expected, as the materials added to the water have longer time to work upon the middle and lower portions.

Substances which have a chemical, as well as a mechanical, action seem to have a greater effect than the substances above mentioned. Magnesium oxide, hard wood ash, lime, and a mixture of three parts lime and one part crude aluminium sulphate were used for these experiments. Where it is desired to purify water by the addition of substances to hasten sedimentation, it is advisable, therefore, to use such substances as have at the same time a chemical action.

ÆTIOLOGY OF ACUTE CROUPOUS PNEUMONIA.

Dr. M. Jakowski (Zeitschrift f. Hygiene, 7 Bd., 1 Heft). J. holds that both the Friedländer's and the Fränkel-Weichselbaum's bacteria may be, under different circumstances, concerned in causing genuine pneumonia. He produced pneumonia in white mice by inoculations of both organisms; recently with the Fränkel-Weichselbaum, some time previously with the Friedlander bacterium. J. does not deny the possibility that neither of the above organisms is concerned, but thinks possibly some other not yet described may be the cause.

EXPERIMENTS ON THE EFFECT OF INFUSION OF COFFEE UPON BACTERIA.

Karl Lüderitz (Zeitschrift f. Hygiene, 7 Bd., 2 Heft). According to these experiments, coffee acts as a disinfectant to quite a considerable extent. Mixed with nutrient media in the proportions given below, it had the effect of preventing the growth of the organisms mentioned: 8-9 p. c. bacillus prodigiosus, 3 p. c. b. of typhoid fever, 2.5 p. c. b. proteus vulgaris, 2 p. c. staphylococcus pyogenes aureus, I p. c. streptococcus of erysipelas and cholera asiat., 0.6 p. c., b. anthracis. In another set of experiments, a few drops of pure cultures were mixed with 8-10 c. c. of 10 p. c. infusion of coffee, and the micro-organisms were all found to have been killed after different lengths of time, as follows: Staph. pyog. aureus, in 4 to 7 days; prodigiosus, 3 to 5 days; prot. vulg., 2 to 4 days; b. of typhoid fever, 2 to 3 days; streptococcus of erysipelas, in 1 day; anthrax bacilli and cholera asiat., within 3 hours. Even anthrax spores were killed in 2 to 4 weeks. The antiseptic properties are not to be ascribed to the

caffein, as this substance is shown to have very weak action in this respect.

ON THE NUMBER OF BACTERIA IN THE GROUND.

John Reimers (Ibid.). Reimers arrives at the following conclusions: "1. The number of bacteria in the superficial layers of the ground is not as large as many authors have stated. It is not over a few million to the cubic centimetre in this neighborhood (Jena-Reviewer).

"2. The numbers remain comparatively large to a certain depth, but are always smaller than on the surface.

"3. With increasing depth there then follows a rather sudden and considerable fall in the numbers, as Fränkel already demonstrated.

"4. The zone in which this sudden decrease takes place, lies between 1 and 2 metres for Jena, as well as for Berlin.

"5. The height or depth at which this zone lies seems to depend principally upon working and using the ground in question. In ground which has been worked it lies deeper than in virgin soil.

"6. Even at quite shallow depths, the ground may be found to be free from bacteria.

"7. The same sorts of bacteria grow more rapidly when found on or near the surface than when found deeper.

"8. This retardation of growth with increasing depth is also a proof that the conditions of life in the deeper layers are not so good as on the surface.

"9. At the shallow depths at which we examined the ground water, the latter showed itself sometimes free of bacteria, sometimes containing them.

"10. Whereas in one set of observations the ground water did not influence the regular decrease of bacteria, in another set the ground. water layer of earth was richer in bacteria than the layer above.

"II. The number of bacteria in the ground does not seem to be materially influenced by the burial of dead bodies. Neither near to nor under the coffins was the number of bacteria greater than at a corresponding depth elsewhere.

12. It was moreover a matter of indifference whether the earth was taken from a grave in which burial had not taken place for thirtyfive years or where it had taken place one and a half years before."

BY GEORGE T. KEMP, PH. D.,

Associate Director of the Department of Physiology and Experimental Therapeutics,
Hoagland Laboratory, Brooklyn.

31

TWO NEW LOCAL ANESTHETICS.

30

46

The Comptes Rendus de la Sociètiè de Biologie (Nov. 15, 1889, p. 617) contains an article by M. E. Gley on the local anesthetic action of ouabaïne and of strophantine. (Action anæsthesiante locale de l'ouabaïne et de la strophantine). These alkaloids were extracted by the methods used by Arnaud, (Comptes Rendus de l'Academie des Sciences, Vol. 106, p. 1011, and Vol. 107, p. 179). Their chemical composition was found by Arnaud to be C, H O12 for ouabaïne, and C11 HO12 for strophantine, thus differing only by CH, which would suggest the inference that they were adjacent members in one of the lines of derivatives of the Cn Hang series. series. From their close chemical relationship, it was inferred that their physiological properties would be very much the same, and this fact was demonstrated by Gley, for their action on the heart, (Comptes Rendus de l'Academie des Sciences, Vol. 107, p. 348). Finding that ouabaïne possessed the property of inducing local anesthesia, Gley supposed that strophantine possessed the same properties, and undertook a series of experiments to test the efficacy of these alkaloids as local anesthetics. Four drops of a 1 to IOCO solution of the chloride of either oubaïne or strophantine, when dropped into the eye of a rabbit, produced a marked diminution of sensibility at the end of five minutes, and in from eight to ten minutes the anesthesia was complete. The cornea could be touched or even pricked without producing any reflex. This anæsthesia may remain for two or three hours. It gradually diminishes, but for an hour and a-half it remains almost absolute. At no time does the eye show signs of irritation or of inflammation. There is neither constriction nor dilatation of the vessels of the conjunctiva. The anesthesia, however, is accompanied by a marked contraction of the pupil, which does not begin to appear until five or ten minutes after the anæsthesia is developed The pupil continues to contract until it almost becomes a pin point, and then gradually begins to dilate to its normal. size, always reaching this stage before the anesthesia passes off. These alkaloids are about 12 times as strong as cocaine, and the anesthesia which they induce is much more lasting. The fact that they do not produce vaso-motor changes gives them an advantage over cocaine in this respect. Whether they will supplant the latter alkaloid remains for the future to show.