634 



THE POPULAR SCIENCE MONTHLY. 



of the storm is also increased, and the re- 

 verse occurs when the area is diminished. 



The general outline of a storm-area is 

 an oval, the longest diameter of which is in 

 direction of the stoi-m's progress. 



Around the centre of a storm are points 

 or lines of equal barometric pressure, and 

 the lines thus formed are called isobaric 

 curves. These are, in shape, irregular oval, 

 and the longer diameter may be, or may not 

 be, in the direction of the storm's longer 

 axis. The prevalent direction is a little 

 north of northeast. 



Prof. Loomis suggested in a former 

 paper that intense and sudden cold arises 

 from vertical movement or displacement of 

 air, by which the warm air suddenly, in 

 some cases almost instantly, rises, the cold 

 air of the upper atmosphere displacing it 

 by its descent. This conclusion is confirmed 

 by recent observations. On the 15th of Jan- 

 uary, 18Y5, the thermometer at Denver in- 

 dicated a fall of temperature of 48 in one 

 hour, and, in another instance cited, the 

 change was 36 in five minutes ! It is sig- 

 nificant that these sudden invasions of cold 

 air appear first, as a rule, on the Eocky 

 Mountains, or contiguous highlands. The 

 presence of mountains seems to favor the 

 development of cold, which would not be 

 the case if the movement of the cold wave 

 was an horizontal one from the arctic I'e- 

 gions, as formerly supposed. 



ExperiniCDts ou the Sense of Taste. In 



a communication to the London Physical 

 Society on subjective sensations of taste, 

 Dr. Stone called attention to two simple 

 experiments, the first of which consists in 

 applying a strong dilution of nitric acid to 

 the root of the tongue by sucking it through 

 a fine glass tube. If pure water be swal- 

 lowed immediately after this, a sweet taste is 

 produced. The author compared this effect 

 to the complementary images seen in the 

 eye after gazing at a powei'fully illuminated 

 body. He then adverted to the taste of the 

 galvanic current. In the well-known ex- 

 periment with pieces of zinc and silver, the 

 zinc is actually dissolved in the saliva. But 

 if one pole of a strong battery (ten Grove's 

 cells in this case) be applied to the nape 

 of the neck, and the other brought to the 

 forehead, besides the flash of light, a strong 



taste is experienced of a metallic charac- 

 ter. It disappears on breaking contact ; 

 and for this reason, as well as from the fact 

 that the tongue is not in the direct line of 

 circuit, and also that there is no substance 

 in the saliva likely by decomposition to 

 cause metallic deposition, it could hardly be 

 referred to chemical action, but must result 

 from direct stimulation of the sensory ap- 

 paratus. Dr. Stone thought that a glimpse 

 might thus be obtained of some correlation 

 between the modus operandi of hearing and 

 sight and that of taste. In the first case, 

 a supplementary and automatic sensation, 

 in the second the effect of a metaUic solu- 

 tion, both entirely subjective, were excited 

 without the presence of any sapid sub- 

 stance. The explanation may be that both 

 classes of phenomena are due to molecular 

 motion. 



Do "Tliorongh-breds" revert? The 



saying is a common one that domesticated 

 animals tend continually to revert to the 

 original or wild type, and do so revert if 

 domesticating influences are withdrawn. At 

 the Hartford meeting of the American As- 

 sociation for the Advancement of Science, 

 W. H, Brewer, Professor of Agriculture in 

 Yale Scientific School, called attention to 

 this subject. He cites remarks made by an 

 eminent scientist at a previous meeting as 

 follows : " The hog has been greatly changed 

 by domestication, and yet when left to him- 

 self he soon returns to the original type. 

 During the late war some of the most im- 

 proved breeds were turned loose and left to 

 shift for themselves. Three years after I 

 found them possessing all the physical char- 

 acters of the wild-boar of Ew-ope. He also 

 stated that a similar fact had been observed 

 with Durham cattle. 



This statement, and all similar ones. Prof. 

 Brewer sharply challenges. He refers to 

 the confidence which owners and breeders 

 of " thorough-breds " have in the perma- 

 nence of acquired qualities ; and says he 

 has failed to find a single instance of rever- 

 sion, nor has he found any one who knows 

 of its having taken place. He suggests that 

 the dogma (reversion) is used as an argu- 

 ment to sustain a certain scientific hypothe- 

 sis. In order to ascertain the facts, Prof. 

 Brewer has issued a circular containing the 



