LYMPHATIC SYSTEM OF SKIN AND MUCOUS MEMBRANES, 883 
benzole on the plan of A. Budge (‘ Archiv f. Mikr. Anat.,’ 
Band xiv., p. 70). This latter is an excellent material for 
injecting the finest rootlets of the lymphatics, for it flows 
with great ease and rapidity and has no influence, hardening 
or otherwise, on the tissue. And in these two respects it is 
greatly preferable to any other injection matter. Berlin blue 
or nitrate of silver possess both, especially the latter, a hard- 
ening influence, and cannot be expected therefore to flow as 
easily into the most distant and finest rootlets as the asphalt- 
benzole solution. The most successful injections of the 
finest rootlets in the connective tissue, fat tissue, hair- 
follicles, and glandular organs have been obtained by this 
last-named reagent. I must, however, add that in some 
cases, even with the asphalt-benzole solution only, the lym- 
phatics of the superficial and deeper plexuses became 
injected, the injection matter not having penetrated into 
the ultimate rootlets, although the former were widely dis- 
tended. 
The solution is made thus: a very concentrated solution 
of asphalt in benzole is prepared, and before using it it is 
mixed with 4 to 1 of its volume of benzole. Asphalt in 
chloroform, as originally employed in C. Ludwig’s labora- 
tory, is not so advantageous, and still less asphalt in 
turpentine. 
8. The injection is carried out in this manner :—A fine 
steel canula, as fine as it can be got, filled with the injection 
material, is gradually pushed in a very oblique direction, as 
horizontal as possible, into the cortum itself. Injections into 
the deep subcutaneous tissue do not yield good results, at 
any rate even in the most successful injections one does not 
generally obtain much more than an injection of the deep 
big lymphatics. 
An ordinary hypodermic syringe filled with the injection 
matter, and fitted into the canula, is then gently and gradu- 
ally emptied into the canula. In a successful injection the 
skin becomes very gradually thicker and swells up, without 
becoming bulged out; the swelling spreads gradually and 
uniformly into the periphery. The mouths of the hatr-fol- 
licles become very conspicuous as depressions owing to the 
parts between them gradually projecting beyond the general 
surface. And this is one of the best signs of a successful 
injection, Continuing the injection the skin becomes still 
more swollen, and the circumference of the injection also 
increases accordingly. 
Owing to the opacity of the epidermis it is not possible 
eyen with a lens to see the lymphatics themselves, the skin 
