ROBERT RUSSELL BENSLEY 41 



The secretion granules of the cells of the glands of Brunner give no reaction 

 when tested by Macallum's method for the microchemical detection of organic phos- 

 phorus. The progress of this reaction is easily controlled, in the case of the glands 

 of Brunner, by observing the effect on the granules in adherent sections of the 

 pancreas, which give a positive reaction for organic phosphorus after treatment for two 

 hours with nitric acid ammonium molybdate. The results with this test in the glands 

 of Brunner, with the exception of the dark tubules of the glands in the rabbit, are 

 absolutely negative. 



Not only do the cells of Brunner not contain the chemical substances which it is 

 possible to recognize in the serous cell either by examining the fresh cell or by employ- 

 ing staining and microchemical methods, but, on the contrary, there is positive evi- 

 dence that they contain something else, which we have good reason to believe is mucin. 



The secretion contained in the cells of the glands of Brunner stains with uniform 

 facility, if certain precautions are taken, in Mayer's alcoholic muchaematein and muci- 

 carrnine. With muchajmatein the precautions necessary to success are as follows: 



If the dilute solution recommended by Mayer is employed, the sections cut in 

 paraffin should be transferred, without attaching them to slides, to benzole, thence 

 to absolute alcohol, thence directly to the staining solution. After five minutes in the 

 latter, they are washed with 70 per cent, alcohol, dehydrated, cleared, and mounted. 



A stronger solution (having the following formula: haematein, 1 g., aluminium 

 chloride, 0.5 g., 70 per cent, alcohol, 100 c.c.) gives better results, and can be used on 

 sections fastened to the slides or on celloidin sections with certainty of S|>eedy and 

 satisfactory results. The degree of acidity of this solution is of some importance. 

 The writer is in the habit of reducing the acidity by diluting his alcohol with tap 

 water containing calcium bicarbonate. After the solution so prepared has stood 

 for a week, it is tested on a section. If the resulting stain is slightly diffuse, a 10 per 

 cent, solution of nitric acid is added, a drop at a time, the staining properties being 

 tested on a section after the addition of each drop of acid. This is kept up until 

 the correct reaction is obtained. The solution so prepared is employed as follows : 



The sections cut in paraffin and fastened to the slide by the albumen or by the 

 water method are treated with benzole followed by absolute alcohol. The slide having 

 been placed on the stage of the microscope, a drop of the staining solution is 

 applied to the section, and the latter is watched under the microscope until a proper 

 depth of color is obtained in the secretion within the cells. It is then rapidly washed 

 in 70 per cent, alcohol, dehydrated, cleared in benzole, and mounted in benzol balsam. 



If the staining is prolonged and the solution is not renewed from time to time, 

 the sections after attaining a maximum depth of color will slowly fade out again, 

 probably owing to reduction in the acidity of the solution by the absorption of 

 ammonia from the atmosphere. Sections should not be washed in water after staining, 

 as this procedure completely removes the stain from the mucous cells. 



This stronger inuchsematein solution stains deep blue the secretion contained in 



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