SCIENTIFIC SUMMAKY. 
321 
an interesting paper on this important question, which was originally read 
before the Institution of Civil Engineers. He considered that the action of 
the “ Race ” off Portland, and of the tidal waves during storms, combined 
to drive the shingle of the old beach at the Bill, and of that portion of it 
which must be spread on the sea-bed westward of Portland, on to the south 
end of the Chesil Bank, whence the shingle was driven northward to 
Abbotsbury and Burton by the action of the wind- waves, having their 
maximum force from the S.S.W., a direction which he showed to be the 
mean of the prevalent winds. Here, these wind- waves became parallel with 
the coast, and the westward movement ceased about Bridport, beyond which 
point the shingle travelled in the opposite direction, viz. from west to east, 
or from the coast of Devon to that of Dorset ; the quartzite pebbles from the 
conglomerate beds of Budleigh Salterton, which travelled from that part of 
the coast eastward to and beyond Sidmouth, gradually diminishing in num- 
bers as they approached Lyme, very few, if any, reaching Bridport. This 
conclusion was in accordance with the facts : — 1. That the pebbles of the 
Devonshire and Dorset strata, which formed the shingle of the “ raised 
beach,” constituted also the bulk of the Chesil Bank. 2. That there 
were also, in that bank, pebbles of the rocks and flint of Portland itself. 
3. That the largest pebbles occurred at the Portland end of the bank, the 
pebbles decreasing gradually in size to Abbotsbury. The large dimensions 
of the bank he attributed to the great accumulative and small lateral action 
of the waves. 
MEDICAL SCIENCE. 
Healing Ulcers by Transplantation of Skin . — The “ Lancet ” of May 22 
states that M. Thiersch, having a patient whose leg had to be amputated in 
consequence of a large and incurable ulcer, thought it a good opportunity 
to examine the changes that take place when portions of skin are im- 
planted on granulating surfaces. For three weeks previously he accordingly 
transplanted portions of skin day by day, the last pieces being applied 
eighteen hours before the amputation. The chief results arrived at were : — 
1. That adhesion occurs without the intervention of any intermediate 
cementing substance. The adherent parts are in immediate application, or 
at most are only separated by a couple of blood-corpuscles. 2. The adhe- 
sion, when complete, takes place by means of the inosculation of vessels, 
which may be observed even eighteen hours after the act of transplantation 
of the new skin. A connection is at this period seen to occur by inter- 
cellular passages extending between the sharply contoured vessels of the 
skin on the one hand and those of the granulations on the other, and these 
intercellular passages become proper vessels in the course of a few days. 
3. At the same time the vessels of the skin beneath the transplanted portion 
undergo secondary changes ; they become wide, irregularly dilated, with 
prominence on their walls, and in fact assume the characters of embryonal 
blood-vessels. 4, True new formation of vessels may perhaps take place 
when the primary inosculation fails. In such cases the epidermis and the 
pipillary bodies fall off after a little while, and the transplantation is 
YOL. XIY. — NO. LYI. Y 
