1890.] MICROSCOPICAL JOURNAL. 87 



MEDICAL MICROSCOPY. 



" The Diagnostic Value of the Phosphates in Pregnancy." — 

 The method used by William B. Gray, M. D.,of Richmond, Va., for 

 precipitating the phosphates is, by adding to the urine in a test-tube 

 about one-third its bulk of magnesium fluid, composed of one part 

 each of sulphate of magnesia, chloride of ammonium, aqua ammonia, 

 and eight parts of water. 



What most interests us, however, is the microscopic appearance of 

 these crystals, for by it can be made the diagnosis of pregnancy weeks 

 in advance of other signs in that condition. One should be thoroughly 

 familiar with the details of the normal crystals before attempting to 

 recognize any departure therefrom. 



The normal triple phosphate is precipitated in those beautiful fea- 

 thery crystals, sometimes a single leaflet, or in stellate forms ; but, 

 however seen, each feather is perfect. If only a fragment is observed, 

 the feathery appearance is preserved to its extreme tip, equally clear 

 on each side of the central stem. 



As soon as conception occurs, the appearance of the triple phosphate 

 changes. It begins to lose its feathery appearance, and disintegrates. 

 The change commences at its tip, and progresses toward its base ; or. 

 only one side of the leaflet may be aflected, leaving the other intact. As 

 the disintegration progresses, only the bare stem may be left, with perhaps 

 a few scraggy points jutting from its sides, and even these stems broken 

 into bits with scarcely any mark to identify them as triple phosphates. 

 These changes commence in the phosphates within twenty days after 

 conception, and continue for several months. After the middle of the 

 seventh month these changes become less pronounced, and gradually 

 approach a more normal type up to the end of gestation. — At?ic?-ican 

 Practitioner ajid N'ews^ March 39, 1890. 



Bacteriology in Johns Hopkins Hospital. — The instruction in 

 Bacteriology is under the charge of Professor W. H. Welch and of Dr. 

 A. C. Abbott, assistant in Bacteriology and Hygiene. 



The rooms for bacteriological work are in the Pathological Labora- 

 tory, and are supplied with all of the apparatus required by modern 

 bacteriological methods, such as those employed in the Hygienic Insti- 

 tute in Berlin. The laboratory has a full set of cultures of pathogenic 

 micro-organisms, and of others useful for study and teaching. 



Opportunities for studying bacteriology are available for students 

 during the entire academic year, the laboi^atory being open on week 

 days from nine o'clock in the morning until six in the evening. As 

 much time can be given to the work as the student has at his disposal. 



In the bacteriological course the student becomes familiar with the 

 pi"eparation of the various culture media, with the principles and meth- 

 ods of sterilization, and with the morphological and biological charac- 

 ters of the micro-organisms which belong to this department of study, 

 particularly with those which cause disease. The methods of making 

 biological examinations of the air, water, and soil, are taught. 



Facilities are afibrded to those who are prepared to undertake orig- 

 inal investigation in bacteriology. 



Dr. J. E. Reeves, of Chattanooga, is professor of pathology, his- 

 tology, and microscopy in the new U. S. Grant University, which has 

 been formed by the union of the Grant Memorial University with the 

 Chattanooga University. 



