January 7, 1897] 
NATURE 233 
THE influence of light upon the discharge of electrified bodies 
has formed the subject of many investigations since Hertz 
observed the effect of ultra-violet light upon the spark of an 
induction coil, less than ten years ago. Since then an extensive 
literature of the subject has grown up, though only a few of the 
more important papers are in English ; so it is difficult to deter- 
mine how far the knowledge of the phenomenon has progressed. 
For this reason, and in view of the evident importance of the 
subject, Mr. Ernest Merritt has prepared an account of the 
investigations which have thus far been published ; his very 
useful summary appearing in Scéezce of December 11 and 
December 18, 1896. It appears from this account that a 
thoroughly satisfactory explanation of the discharging action of 
light has not yet been found, and that many questions con- 
cerning the phenomenon remain to be settled by further 
experimental investigation. 
Tue January number of Scéence Progress opens with an 
article, by Prof.-H. A. Miers, F.R.S., on Dr. Lehmann’s 
“Liquid Crystals.” Two of these remarkable bodies are azo- 
xyphenol and azoxyanisol. When crystals of azoxyphenol are 
warmed on a microscopic slide, they are suddenly transformed, 
at a temperature of 134°, into a substance which preserves the 
outline of the crystal, is strikingly doubly-refractive, and be- 
haves like a true crystal when rotated between crossed Nicols, 
but is nevertheless a liquid. If the preparation be still further 
warmed, it passes at 165° into a third modification which is 
also liquid, but not doubly-refractive. It is possible to con- 
trive that this molten substance shall contain small portions of 
the first, birefringent, liquid which float about in it as perfectly 
spherical drops, and are regarded by Lehmann as really liquid 
crystals. Crystals of azoxyphenol behave in a similar way, the 
changes taking place at 116° and 134°. The investigation of 
these curious birefringent liquids has an important bearing upon 
current views regarding the structure of solids and liquids. 
BALMOKAND, a cloth-seller of Rawalpindi, has written a 
remarkable brochure, entitled ‘‘ The Priceless Gem” (The Mitra 
Vilasa Press, Lahore), which advocates what may be regarded as 
a ‘* puritanical” movement in modern Hinduism. It would be 
easy to indite a cheap criticism of the literary style, the authorities 
quoted, and of the translation from the original Urdu into 
““baboo” English, but it is a more grateful task to recognise 
and make known the serious aim of the author. Being struck 
by the contrast between the former learning, wealth and power 
of ancient India, and her present ‘‘ ignorance, indolence, in- 
dulgence . . . with all other vices and evils,” Balmokand, by 
“* long contemplation and continuous thought,” came to the con- 
clusion that this is due to disregard of the ancient Bara custom ; 
by which a man and woman of similar éavanz being joined in 
marriage **should become for their whole life a loving and affec- 
tionate couple.” The author waxes eloquent on the joys of a 
happy marriage, and on the chivalrous protection, courtesy and 
deference that is due to woman from man, and sustains his 
position by quotations from the Hindu sacred writings. He 
is also strong on the crime of infant marriage, and relies on 
ancient authority for maintaining that neither sex should 
marry before the twenty-fifth or twenty-sixth year. Most 
of the ills of modern India are ascribed to the breaking 
up into innumerable castes of the four primitive darars— 
Brahmin, Kshatrya, Vaisha and Sudra. The psychological 
and religious tendencies of the members of the four darans are 
described, and the decadent social groups produced by various 
degrees of miscegenation are detailed. The four primitive 
castes were communities of relationship ; he would resuscitate 
the classes, but would admit entrance into them by the casting 
of a horoscope. The selection of suitable partners in life is 
rightly regarded as a most important matter which affects family 
NO. 1419, VOL. 55 | 
happiness and the well-being of the next generation: this 
selection is, however, not to be made by wise consideration in 
the European sense of the term, but, like all the other events of 
life, is to be determined by divination. The main interest of 
the pamphlet lies in the picture that it gives of the working of 
the mind of an enthusiast and visionary belonging to an entirely 
different world from our own ; it is a practical lesson in com- 
parative psychology. 
A GRAVE-FIND at Vitzke, in Altmark, probably belonging to 
about the end of the fourth century of our era, is described and 
figured by E. Krause in Globus (Band Ixx. Nr. 17). In the 
same number of the journal is the annotated translation (in 
German) of the Polynesian song of the saving of Nga-Upoko-E- 
Rua, the daughter of Potikitanas, in which are embodied myths of 
origin. Dr. A. Vierkandt follows with a sociological study on 
the family. The succeeding number of G/odws has an illustrated 
article showing the skill in portraiture of the ancient Egyptian 
sculptors. P. Dittrich contributes a study of the plans of houses 
and of rudimentary courtyards in Schlesien. Schlesien was 
originally a German land; during the wandering of the peoples 
it was peopled by Slavs, but later, especially in the west, German 
influence made itself felt. It is not too soon that such in- 
vestigations have been undertaken, for the thrashing-machine is 
replacing the flail, and gradually the history of the old culture 
will become obliterated. Would that we had such investigations 
in our own islands ! 
SoME experiments have been made by Wernicke on the 
vitality of cholera vibrios under particularly interesting conditions. 
A model aquarium was constructed, and in it water-weeds of 
all descriptions were planted ; it was supplied with fish, and 
there was no lack of ordinary water bacteria, in addition to 
which about five milliards of cholera germs were introduced. 
The vessel and its contents stood in the laboratory, and was 
exposed to both diffused light as well as to direct sunshine. 
Nearly three months after the cholera vibrios had been added, 
they could be detected in the water, as also on the water-weeds ; 
whilst even after the lapse of three months they were isolated 
from the mud at the bottom. Later, however, all traces 
of them disappeared. Wernicke is of opinion that mud affords 
a very suitable nidus for the preservation of cholera vibrios, 
and believes that, had he allowed less light to gain access to 
his glass vessel and its contents, he would have identified them 
even longer ; doubtless in the beds of rivers they would preserve 
their vitality for a considerably longer period. No alteration, 
either in their morphological or biological functions, could be 
traced in'these cholera vibrios in consequence of their surroundings; 
but whilst Wernicke states that they were highly virulent when 
they were first introduced, he unfortunately omits to say if their 
pathogenic properties suffered any diminution in the interval. 
‘Tue principal household insects of the United States” are 
described by L. O. Howard and C. L. Marlatt in Bulletin 
No. 4, published by the United States Department of Agri- 
culture. The work contains numerous original observations, 
and will interest the European reader by giving him a clear and 
trustworthy account of some of the insect pests which infest 
houses in the Southern States of America. Among the insects 
which are equally well known in Europe and America is the 
bed-bug, which Prof. Marlatt informs us was said by Kalm in 
1748 to be plentiful in the English colonies and in Canada, 
though unknown among the Indians. We believe there is 
evidence of its having been abundant in Jamaica early in the 
last century. Prof. Marlatt thinks that the irritation caused 
by its attacks is due simply to the puncture, and that no 
poison is injected; but this is certainly an open question, 
and requires further investigation. A far more formidable 
insect, however, is Conorhinus sanguisuga, Leconte, called by 
