186 PREPARATION AND MOUNTING 
however, the acetate of potash also is formed and as this 
salt has an injurious action upon the cells, Dr. Goadby 
recommends nitrate of lead to be used, which preserves 
rather than destroys them. THe also advises the addition 
-of two ounces of gelatine dissolved in eight ounces of water, 
to eight ounces of the saturated solution of each salt; but 
with this addition the hot-water bath would be required to 
keep the injecting fluid liquid. ; 
27. Many of these are best mounted in balsam, in the 
same manner as those made in the ordinary way; whilst 
others are best shown when preserved in liquids, for which 
purpose Goadby’s fluid may be employed. 
28. This mode of making injections with chromate of lead 
is deemed by many the best, especially where one colour 
only is employed. But it must be allowed that there is a 
little more danger of failure where two separate fluids are 
used for the same vessels. 
29. We will now consider the best manner of making 
transparent injections, which, for many purposes, possess an 
undoubted advantage over opaque ones. But it must be 
remembered that there are certain subjects to which no 
transparent injection could be applied, as they are too thick 
when in their natural state, and cutting would destroy all 
‘that beauty which is shown by the different parts in their 
relative adaptation. For those objects, however, which 
must be cut into sections to display their wonders, or are 
naturally thin—such as some of the finer tissues, livers, 
kidneys, &c..—transparency is a great acquisition, and 
enables us to understand the arrangement of the vessels 
more perfectly. Again, another advantage is the simplicity 
of the process; no hot water is needed with some pre- 
parations, either for the subject or the injecting fluid, which 
runs into the minute vessels thoroughly and easily, whilst 
the cost is small. 
30. For this kind of injection no colour is so commonly 
used as Prussian blue. It is not a good one, as was before 
stated, for any opaque object, the light reflected from it 
