210 
POrULAR SCIENCE REVIEW. 
made in conjunction with Dr. Verga. This paper gave rise to some observations 
from Dr. Bizzozero, tending to show the apparent discord of results obtained 
in this matter by many experimenters ; this opinion was confirmed in a few 
words by Dr. Verga. 
Death of M. Poisseuille. — We regret to have to record since our last issue 
the death of M. Poisseuille, the celebrated inventor of the Hsemadynamo- 
meter. lie had reached the age of 73 years. 
Faradization in Physiognomy. — M. Duchenne, so well known for his 
advocacy of the induction coil in the treatment of nervous diseases, has 
been apptying the art to the study of physiognomy. He has been trying to 
study the effects of the contraction of the facial muscles on the expression, 
and in order to prove this he has adopted the plan of “Faradizing ” the 
different muscles, and then photographing the face while the muscle is in con- 
traction. His description of his results is reviewed in the current number of 
the American Psychological Journal , and several capital photographs from 
Duchenne’s negatives accompany the review. 
The Physiology of the Iris . — The question as to whether the iris is provided 
with a special set of dilator and contractor muscles is among the most diffi- 
cult in physiology. The subject has recently been taken up by various 
continental physiologists, and among these by M. Dogiel, who has written 
a paper in a recent number of Max Schtdtze’s Archiv fur mikroskopische 
Anatomie. This observer states he has demonstrated microscopically the 
presence of both a dilator and a sphincter in a considerable number of 
animals with the greatest certainty. These being admitted, then, the 
next point is to determine in what way the movements of the iris are in- 
fluenced by the third nerve and the sympathetic respectively. To deter- 
mine this it seemed to be of great importance to discover how the iris 
behaves when both sets of fibres are either directly or indirectly through 
these nerves slimulated to the utmost extent ; and this may be effected 
either by the application of two oppositely-charged electrodes to the fibres, 
or by acting on one set of the fibres with one electrode and the nerve 
supplying the opposite set of fibres with the other electrode, or by stimu- 
lating both nerves coincidently. When both sets of fibres were directly 
stimulated, the pupil retained its average diameter and circular form, or 
occasionally became elliptical. When one set of muscles was directly 
stimulated and the other excited through the nerves, no remarkable prepon- 
derance of one over the other set was observed ; but when both nerves were 
simultaneously excited the action of the third was decidedly strongest, 
strong contraction of the pupil resulting, and it was noticed that the action 
of the stimulus, when applied through the nerves, was in all instances much 
greater than when applied directly. 
MINERALOGY AND METALLURGY. 
Crystal* in Iron as seen u'ith the Microscope. — Some recent microscopical 
examinations of iron and steel have been made by M. Schott, and have led 
him to believe that all crystals of iron are of the form of a double pyramid, 
the axis of which is variable, as compared with the size of the base. The 
