Benson A. Cohoe 171 
at the end of from six to nine hours, with a dosage of 0.014 gms. per 
kilo of body weight of the animal. Profuse salivation commenced as a 
rule in from three to five minutes after the subcutaneous injection of this 
amount of pilocarpine, although certain of the animals manifested a 
marked idiosyncrasy towards the drug, as a result of which the stages 
of secretion as evidenced in sections of the gland revealed considerable 
variation at the end of the same number of hours, and with equivalent 
doses. In this manner a series of stages, taken at intervals of two hours 
was obtained, varying from the normal resting gland, through the 
phases of secretion, to a time twenty-four hours after the first admin- 
istration of pilocarpine. At the end of this length of time it was 
found that the gland had again assumed a resting condition and that 
its microscopic appearance was that of a normal, unstimulated gland. 
In each case fresh sections of the gland were examined in a medium 
of aqueous humor of the eye, which furnished a fluid which was at 
once isotonic and did not dissolve the granules within the cells. In 
addition to aqueous humor various reagents, referred to later, were used 
upon the fresh sections in order to study the conduct of the granules 
in different media. Small pieces of the remainder of the gland were 
hardened in different fixing reagents such as alcohol, formalin (10 per 
cent solution), Carnoy’s fluid, aqueous sublimate, Kopsch’s fluid, Zenker’s 
fluid, and others. 
The majority of these hardening fluids, with the exception of Kopsch’s 
fluid, afforded little or no granular fixation. A modification of Kopsch’s 
fluid, suggested by Dr. R. R. Bensley, consisting of a mixture of equal 
parts of Kopsch’s fluid and saturated alcoholic sublimate, to which is 
added an equal volume of distilled water, gave better results than the 
simple Kopsch’s fluid and served to fix the granules in a striking 
manner. A saturated solution of sublimate in normal salt solution gave 
good cellular fixation with scarcely any shrinkage, but did not preserve 
the granules. The most satisfactory results were obtained by the use 
of Bensley’s alcoholic-bichromate-sublimate, which in addition to 
preservation of the granules, gave excellent cytoplasmic fixation. Even 
with this fluid, however, as with all of the reagents before mentioned, 
some shrinkage of the distal tubular cells was produced. rik Miiller, 96, 
has called attention to the difficulty in avoiding shrinkage in the fixation 
of these cells. After fixation the tissue was imbedded in paraffin and thin 
sections made varying from 2-5 micra in thickness. 
For staining purposes Heidenhain’s iron hematoxylin, followed by 
12 
