380 PROCEEDINGS OF SECTION C. 
the extreme smallness of the interval of time concerned, the 
radiation of heat would be small, consequently the condensation 
would be concentrated about the tube itself. 
The fulgurites from Kensington present no new feature as 
regards their form or general character. Externally they are 
rough, somewhat whiter than the surrounding sand; inside they 
are enamel-like, from the glassy surface of the fused silica. Under 
the microscope the fused material is seen to be full of small 
vesicles ; the surrounding sand fused in the oxyhydrogen jet pre- 
sents an almost identical appearance. In chemical composition 
the fulgurites are substantially the same as the surrounding sand. 
Unfortunately, too great a mass of sand would have had to be 
moved to reach the terminals of the tubes. After following one 
for a length of 10 feet along its course, there appeared no indica- 
tion of a change in size, and further excavation was impracticable. 
The photograph herewith [exhibited] and the exhibits give a defi- 
nite idea of the form and characteristics of fulgurites formed in 
loose sand. The photographs were taken by one of us (J. M. 
Curran), and shew the section as well as a longitudinal view of 
the tubes. 
The specific gravity of the fulgurite material was found to be 
2-1, and its chemical composition by the analysis of one of us 
(J. M. Curran) to be SiO, 93:4 7%, Al,O, 5 7%, Fe,O; trace. 
The somewhat lengthy bibliography of the subject, which here 
follows was prepared by one of us (G. H. Knibbs) with the view 
to forming a nucleus for a more perfect record. It is hoped that 
it includes at least the more important part of the existing litera- 
ture on the subject, but since it has been somewhat hurriedly pre- 
pared, some papers have perhaps been missed. If any member 
of the section possessing references not included, will kindly allow 
them to be added, with proper acknowledgment, the bibliography 
will be correspondingly improved, and will more nearly achieve 
its object. [No addition has been made. ] 
BIBLIOGRAPHY OF FULGURITES. 
1 _Hermann.—Maslographia, oder Beschreibung des schlesischen 
Massel, etc. von. Leonh. Dav. Hermann, Breigae, 1711. The 
fulgurites were catalogued as Osteocolla Maslensis, que fossile 
aborescens Maslense, p. 189. 
? Joh. Bernh. de Fischer.—De foeno sub combustione per ful- 
minis ignem in massam seu scoriam calecaream redacto. Nov. 
Act. Soc. Nat. Curios. Vol. 3, pp. 221, et seq. 
3 Buchholz—Untersuchung einer Schlacke, die Gelegenheit 
eines Wetterschlags in einem Heuhaufen entstanden. Natur- 
forscher. St. 4, pp. 227, et seq. 
