N. D. C. Hodges—Size of Molecules, 135 
The composition obtained has great interest, since it shows 
that this most fusible part of the Kilauea lavas has almost pre- 
cisely the composition of ordinary doleryte (=basalt=diabase, 
essentially). I cite for comparison an analysis by G. W. Hawes 
of the “trap” of West Rock (New Haven, Conn.), which agrees 
closely with the average composition of this basic rock. 
SiO. AlO; FeO, FeO MnO MgO CaO Na,O K,O ign 
Pélé’s Hair 50°75 16°54 2°10 7°88 wt, 765 11°96 2°13 0°56 0°35—99-92 
West Rock “trap” 51°80 14:21 3°55 8-26 0°42 7°63 10°68 2°15 0°39 0°63=99-72 
[ + phosphoric acid 0°14 
igneous roc 
nimportant paper on the microscopic characters of Pélé’s 
Hair has been published at. Tubingen (in 1877) by C: Fr. W. 
illustrates by figures, the following facts respecting Pélé’s Hair. 
e fibers are sometimes bent and coalesced into loops; often 
are tubular; frequently contain air bubbles, and occasionally 
microlites. i n enlargement of the diameter 
whenever a crystal (or microlite) exists within, and also about 
many of the air-cavities. The crystals are mostly rhombic, but 
as to their kinds the author makes no suggestion. 
ArT. XXIII.— On the size of Molecules; by N. D. C. Hopg@es. 
