. A text-book upon the pathogenic Bacteria and Protozoa for students of medicine and physicians. Bacteriology; Pathogenic bacteria; Protozoa. 720 Sj^hilis 1. Cover the smear with a i per cent, aqueous solution of osriiic acid, and per- mit it to act for thirty seconds. This solution acts as a fixative and mordant. 2. Wash thoroughly in running water. 3. Cover the smear with a i: 100 dilution of Liquor plumbi subacetatis (freshly prepared). Permit it to act for ten seconds. The lead unites with the albumin to form lead albuminate which is insoluble in water. 4. Wash thoroughly in running water.


. A text-book upon the pathogenic Bacteria and Protozoa for students of medicine and physicians. Bacteriology; Pathogenic bacteria; Protozoa. 720 Sj^hilis 1. Cover the smear with a i per cent, aqueous solution of osriiic acid, and per- mit it to act for thirty seconds. This solution acts as a fixative and mordant. 2. Wash thoroughly in running water. 3. Cover the smear with a i: 100 dilution of Liquor plumbi subacetatis (freshly prepared). Permit it to act for ten seconds. The lead unites with the albumin to form lead albuminate which is insoluble in water. 4. Wash thoroughly in running water. 5. Cover the smear with a 10 per cent, aqueous solution of sodium sulphid. This is to act ten seconds, during which the salt transforms the lead albuminate into lead sulphid and causes the preparation to turn brown. The osmic acid when reapplied causes it to become black. 6. Wash thoroughly in running water. The whole process is to be repeated in exactly the same manner three times, the washings all being very thorough. The preparation is then dried and mounted in Canada balsam. The micro-organisms and cellular detritus are stained Fig. 295.—Treponema pallidum in the periosteum near an epiphysis (Bertarelli). When serum from a primary sore or other syphilitic lesion is treated by these methods, a number of the spirochaeta appear well stained and a number very palely stained, so that one is in doubt whether there may be many others unstained, and this seems to be the case, for when similar smears are treated by other methods many more can be found. Stern* has applied the method of silver incrustation to the ex- amination of films by the following simple procedure: Spreads are made in the usual manner, dried in the air, and then for a few hours in an incubating ovenat 37°C. They are next placed in a 10 per cent, solution of nitrate of silver in a colorless glass receptacle and allowed to rest in the diffused daylight of a comfortably lighted room for a few hours, unti


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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbacteri, bookyear1916