5 io 



THE POPULAR SCIENCE MONTHLY. 



are liable to be occupied by people during 

 a thunder-storm an iron balcony, for in- 

 stance. In such cases it is better not to 

 have the iron connected with the conductor, 

 for there is some risk of persons standing 

 on the balcony furnishing a path for the 

 lightning to the rod. 



North American Archaeology. The di- 

 rectors of the Smithsonian Institution con- 

 template the publication of an exhaustive 

 work on the antiquities of North America, 

 and earnestly invite the cooperation of 

 archaeologists and of all who may be pos- 

 sessed of information concerning the abo- 

 riginal history of North America. The an- 

 cient monuments to be described in the work 

 are mounds and earthworks, shell-heaps, cave 

 and cliff dwellings, masonry, sculptured slabs 

 or carved images, inscriptions, and rock- 

 paintings, graves and cemeteries, aboriginal 

 quarries, and salt-works, caches or deposits 

 of objects in large quantities, workshops or 

 places of ancient aboriginal industry, an- 

 cient roads or trails, reservoirs and aque- 

 ducts. In addition to original records and 

 descriptions of the objects here enumerated, 

 the Smithsonian Institution desires to ob- 

 tain copies of all books, memoirs, pamphlets, 

 extracts from periodicals, and newspaper 

 clippings, having any relation whatever to 

 American archaeology. Information is fur- 

 ther solicited concerning all collections of 

 American antiquities, however small, whether 

 in private hands or in public museums. Any 

 one can obtain, on application to the Smith- 

 sonian Institution, its " Circular in Refer- 

 ence to American Archaeology," in which 

 are stated in detail the different subjects 

 concerning which specific information is 

 wanted. 



A New Fact in Natural History. In the 



books of Leviticus and Deuteronomy it is 

 forbidden to eat any creature living in the 

 waters that " hath not fins and scales." Of 

 such animals it is written : " They shall be 

 an abomination unto you ; ye shall not eat 

 of their flesh, but ye shall have their car- 

 casses in abomination." Christians, at least 

 modern Christians, are not wont to hold 

 oysters as " unclean " and " an abomina- 

 tion," notwithstanding the very high au- 

 thority on which they are so declared to be 



in the Holy Scriptures. But the Jew still 

 obeys the divine command, as of old ; hence 

 the devout Hebrew knows nothing, from 

 personal observation, of the delicate flavor 

 of the oyster, and no doubt that savory 

 bivalve has oftentimes been a stumbling- 

 block and a scandal for the weaker ones of 

 the children of Israel. But a truly won- 

 derful discovery has been made by a learned 

 rabbi in England, which takes the oyster 

 out of the class of things forbidden, and 

 makes it as harmless to the conscience as, 

 doubtless, it will be grateful to the palate 

 of the Jew. This rabbi has read Mr. Dar- 

 win's works, and read them to some pur- 

 pose, for he finds that, " in consequence of 

 the theories" of that famous naturalist, 

 " oysters are plants, and may therefore be 

 eaten by Jews." We hasten to add that 

 as yet the rabbi's views are merely mat- 

 ters of private opinion, and hence no safe 

 guide for consciences ; but a grand council 

 will before long be summoned to render 

 authoritative judgment in the matter. Its 

 decision will be awaited with no little in- 

 terest. It is to be hoped that the vegeta- 

 ble side will prevail. One strong argu- 

 ment in its favor is the notorious fact that 

 oysters are planted, the result of course be- 

 ing the oyster-plant. 



Peculiarities of Vision. Mr. Galton, in 

 his paper on " Composite Portraits " (see 

 page 465 of this number), observes that 

 "the two separate impressions received by 

 the brain through the stereoscope do not 

 seem to be relatively constant in their vivid- 

 ness, but sometimes the image seen by the left 

 eye prevails over that seen by the rigJtt, and 

 vice versa." This remark has elicited from 

 a correspondent of Nature a communication 

 in which he describes a very curious defect 

 in his own eyesight. This correspondent's 

 right eye is fairly long-sighted, but the left 

 eye is short-sighted. Print which is read 

 distinctly by the one at the distance of eigh- 

 teen inches, cannot be easily read by the 

 other at a distance of over eight and a 

 quarter inches. The result of this is, that 

 the right the long-sighted eye closes in- 

 voluntarily when he reads. Again, when 

 he looks intently at a distant view, the left 

 or short-sighted eye shuts occasionally. 

 When both eyes are open he has two sep- 



