43 



THE POPULAR SCIENCE MONTHLY. 



showing its head and the other one the end 

 of its tail. They are probably intended to 

 be seals. On the same side of the horn arc 

 three figures of identical form, the meaning 

 of which is not clear, and a figure that may 

 be a hemipterous insect. 11. Gaudry has 

 no doubt of the authenticity of this speci- 

 men, for he is assured by M. Paignon, who 

 is a lawyer and publicist of repute, and in- 

 terested in prehistoric studies, that it was 

 found in his presence by his own workmen 

 while digging out the bone-earth from the 

 bottom of the cave. 



" Educating up." Dr. Andrew Wilson 

 suggests that we might with advantage dis- 

 miss some of the less useful topics from 

 the curriculum of the common schools, and 

 supplant them by other topics of vital inter- 

 est to every class of the community. Boys 

 and girls, for instance, are frequently kept 

 working at modern languages, drawing, 

 classics, and other branches, when the teach- 

 ing of physiology, health, and domestic 

 economy would be of infinitely greater ad- 

 vantage to them in afterlife. Some people 

 would think this to be educating down, but 

 Dr. Wilson asks : " Is it certain that by 

 limiting the ' extras ' or what are undoubt- 

 edly often useless topics in education in 

 so far as the social life of many of the pu- 

 pils is concerned we should be educating 

 down at all ? In all likelihood we should 

 rather be practicing the reverse procedure. 

 By imparting a knowledge of the laws of 

 health and economy, we should be enabling 

 the teacher to discharge his duties in a fuller 

 and truer sense than before. . . . Individu- 

 al culture of such subjects lies at the root 

 of all national advance in health and pros- 

 perity. As several writers have shown, the 

 remedy for much of the misery and poverty 

 now existent lies in the better use of the 

 hours spent at school." 



An Endnlatory Theory of Odors. M. 



P. Leclerc has propounded a theory that 

 odor is, like light and sound, a phenomenon 

 of undulation. He cites in support of his 

 view that many substances, like sulphur 

 and copper, do not emit odors until they 

 are rubbed, and it is more reasonable to 

 suppose that the rubbings cause undula- 

 tions than that under that condition the 



substances emit matter which can not be 

 detected except as a smell. Again, arseni- 

 ous acid when thrown upon a burning coal, 

 gives out thick gray fumes and an odor of 

 garlic. In the solid state it has no smell, 

 and no more in the vaporous state if no 

 chemical change takes place in volatilizing 

 it. But, when it is thrown upon the hot 

 coal, a reduction takes place to arsenic, that 

 is volatilized and then reoxidized on com- 

 ing in contact with the air, and we have a 

 smell accompanying the chemical action the 

 same as in many other cases we have light 

 or heat in connection with it. M. Leclerc, 

 continuing his experiments with a rather 

 imperfect instrument, claims to have pro- 

 duced interference of odors analogous with 

 the interference phenomena of light. 



Some British Weeds. British farms and 

 gardens are troubled by about a hundred 

 and thirty species of weeds, annuals and 

 perennials, with about a dozen biennials. 

 Among the most troublesome and mischiev- 

 ous of them are the bind-weeds and the 

 couch-grass, which will start to grow from 

 so small a piece of root that it is almost 

 impossible to get rid of them. The couch- 

 grass is nearly in place in Italy, where the 

 white, underground stems, which contain a 

 considerable quantity of starch, are gath- 

 ered and taken to market, to be sold as 

 food for cattle and horses. A variety of 

 this grass, called matt-grass, also finds a 

 place in Holland, where it is put to use for 

 binding together the sandy dunes and flat3 

 by the sea. Some weeds have a marvelous 

 power of increase. The history of the ox- 

 eye daisy in this country illustrates this 

 property. Some seeds of the plant found 

 their way in packages to the Island of Co- 

 lonsay, in the west of Scotland; in the 

 course of a few years the ox-eye had taken 

 possession of the whole island. The com- 

 mon yellow toad-flax was introduced as a 

 garden-flower by a Mr. Ranstead, and i3 

 known as the Ranstead weed. Chickweed is 

 said to have been introduced as a bird-seed. 

 The Scotch thistle arrived in a bed-tick 

 filled with its down. The down, having 

 been replaced with feathers, was thrown 

 away, and soon found a congenial home. 

 Some American plants, particularly the wa- 

 ter-weed (Anacharsis ahinasfrum), have nat- 



