266 THE AMERICAN MONTHLY [Aug 



washed and ag"ain boiled one-half hour; the liquid is then 

 filtered throug-h cotton, then throug-h paper, and serves as 

 the watery basis of the ag'ar. One per cent of peptone, Y?. 

 per cent of salt and \}{ per cent of agar are added to one 

 liter of potato water and the whole boiled over a flame for 

 about three quarters of an hour. The medium is then 

 titrated to determine its reaction, and broug-ht to react 

 O.lS acid phenolphthalein. If alkali (Na O H) or acid (H 

 CI) is added, the boiling- is continued one-half hour long^er. 

 The medium is filtered throug-h absorbent cotton steril- 

 ized for three consecutive days at twenty-four hour 

 intervals, and then put into test tubes and sterilized. After 

 the last sterilization the medium is allowed to harden on 

 the slant. 



' 1IEDI€AL MICROSCOPY. 



Diagnosis of Pregnancy. — Dr. Park of Philadelphia 

 reports that preg-nancy may be diag-nosed as early as 

 twenty days after its occurence by a study of the triple 

 phosphates in the urine. The feathery appearance dis- 

 appears from the tips of the crystals sometimes from one 

 side only at first, followed by a like disappearance from 

 the other side. If the fetus dies the normal appearance 

 is renewed. This diag-nosis of course afford;:, the advan- 

 tage that it can be made without suspicion on the part of 

 the patient. ^ — Am. Gyn. and Obst. Jour. 



Examination of Blood in Diphtheria. — A microscopic 

 examination of the blood will enable us to make a more 

 intelligent diagnosis in diphtheria. If the myelocytes 

 — i. e., mono-nuclear white blood corpuscles, with ncutro- 

 phile granules (excluding both the mono-nuclear leucc- 

 cytes poor in chromatin, considered by Frankel as charac- 

 teristic of leukaemia, and also the large mono-nuclear 

 eosinophile cells of Muller and Rieder) — are present in 

 quantities of two per cent, or more in the blood of a diph- 

 theria patient, the patient will die; but a smaller percentage 

 does not of itself justify a favorable prognosis. The 

 highest percentages found in diphthex'ia patients who re- 



