1891.] MICROSCOPICAL JOURNAL. 9 



per 1 part, water 40 parts. All ingredients must be free from iron. 

 Grind the alum, logwood extract, and sulphate of copper in a mortar, 

 and when powdered, add sufficient water to form a thin paste, leave 

 for one or two days, with occasional stirring, and then filter." The 

 stain made from a similar receipt was found to work very efficiently, 

 and at the same time it can be easily made. 



Picric acid, which has the property of staining yellow such structures 

 as the epithelial surfaces, requires but solution in distilled water to fit 

 it for use. Sometimes it is used in combination with carmine solution ; 

 but it is preferable to use them separately or conjointly as cases may 

 require. The sections which have been cut may be placed in either of 

 these as the student may choose, but he should bear in mind the ad- 

 vantage of using these stains diluted, and of slowly staining them. 

 For this purpose watch-glasses or shallow glass dishes will be found 

 of great use. The sections, being placed in the staining solution in 

 one of these, may be covered up and left for a short interval, till the 

 staining is considered deep enough, when it may be removed to clean 

 distilled water, and examined, any stray fragments being removed with 

 a camel's-hair brush kept for that purpose. If the section is sufficiently 

 stained it may be transferred to a small quantity of absolute alcohol to 

 dehydrate it. Having been steeped in this a short time, put a drop 

 of oil of cloves on a glass slide, and taking up the section with a pair 

 of forceps, drain it from the spirit, and when nearly di*y place it on 

 the top of the oil of cloves, which, thus taking the place of the spirit as 

 it evaporates, vs^ill clear the section and render it transparent. If the 

 section is left too long in the oil of cloves it becomes shrunken and 

 distorted ; therefore, as soon as it is quite evenly clear, it may be drained 

 from the oil and mounted in balsam, preferably the balsam and benzole 

 solution. This, then, is the modus ope7'andi to be observed in all 

 section mounting, subject to varying treatment when other mounting 

 media are employed. 



The beauty of some vegetable sections if double stained, and this does 

 not entail 'much difficulty in its accomplishment, will be an addition to 

 the student's pleasure if directions are here given. Judson's scarlet dye 

 may be added to water till a good color is obtained, when the solution 

 must be filtered through blotting-paper. Judson's blue dye may be dis- 

 solved in methylated alcohol, and the solution filtered. These solutions, 

 well corked, keep for a considerable time. Prepare two watch-glasses 

 and put a little of the red solution in one, in which place the section. 

 When it becomes stained an uniform red, remove it to the other watch- 

 glass, in which pour some of the blue. This will drive out the red 

 stain from all but those definite portions of the section to which the red 

 will cling with great tenacity ; after which it may be treated according 

 to the foregoing directions, and mounted permanently. 



The subject of bacilli, and their occurrence in the sputa of phthisical 

 patients, and their staining are of interest. The sputum is spread in a 

 thin layer on a cover-glass, and dried at a temperature of 3i3°-23o°, or 

 passed three or four times through the flame of a spirit lamp. The 

 staining fluid is prepared as follows : 5 c.c. pure aniline added to 100 

 c.c. of distilled water, well shaken and then filtered through moistened 

 blotting-paper. To this mixture a saturated alcoholic solution of fuch- 

 sine, methyl violet, or gentian violet is added, till precipitation com- 



