441 
Nachdruck verboten. 
A new fixing Fluid for animal Tissues. 
By Gustav Mann, MB., CM., Physiological Laboratory. 
University of Edinburgh. 
The following is a modification of the picro - corrosive - alcohol 
method devised by me some time ago for preserving vegetable tissues, 
an account of which was published in the Transactions of the Botanical 
Society of Edinburgh). With the object of fixing the various proteids 
and albumins of animal tissues before they have had time to split up 
and part with their water, — for I believe that normally comparatively 
little water exists in a free state in living animal tissue —, I can 
recommend a fluid composed as follows: 
Absolute alcohol 100 ccm. 
Picric acid 4 grm. 
Corrosive sublimate 15 grm. 
Tannic acid 6—8erm. 
The object of the addition of tannic acid is to prevent undue 
hardening of the tissue, for it was found absolutely impossible to 
make sections of dense animal tissues fixed by the botanical fluid, 
whereas the addition of a certain amount of tannic acid gave them 
only the consistency of indiarubber. 
In order to obtain good results it is essential: 
1) To use only living tissue. 
2) The pieces of tissue should not exceed 0,5—1 cm in thickness. 
3) An amount of fluid 20 times the bulk of the tissue must be 
used, at the respective temperature of the animal. 
4) Leave the tissue in the above solution from 12 to 24 hours, 
after which it must be (a) either washed twice in absolute 
alcohol for 5 hours each time, or (b) washed for 2 hours in 
running water, then placed for 12 hours in 30°/, alcohol con- 
taining sufficient tincture of iodine to give it a brown colour. 
Then for 12 hours more in 50°/, alcohol containing iodide 
of Potassium. Transfer to 50°/, alcohol for 3 hours, and 
1) Transactions and Proceedings of the Botanical Society of Edinburgh, 
Vol. XVIII, p. 432, 
