550 



SCIENCE. 



[Vol. VII., No. 176 



It is the aim of the author to state as fully as 

 may be the constitution of every substance con- 

 cerning which any thing is said, and original 

 sources of information are indicated when known. 

 For the convenience of readers who do not have 

 access to large libraries, reference is also made to 

 such related matter as may be found in Watt's 

 4 Dictionary of chemistry,' or in the Journal of 

 the Chemical society in London. The system of 

 arrangement is simple, and the material acces- 

 sible. The work, far more complete and conven- 

 ient than any thing of its scope previously at- 

 tempted, is a monument of patient industry in- 

 telligently applied. 



— The wealth and thoroughness of information 

 contained in Dr. O. Stoll's book on Guatemala 

 (Guatemala, Leipzig, Brockhaus, 1886, 8°) shows 

 at sight that the author is not one of the common 

 travellers trying to perpetuate the memory of 

 their sights in foreign countries. Stoll's main 

 purpose in expatriating himself for five years to 

 practise medicine in a land like that, was the 

 thorough study of the aborigines. This enabled 

 him to acquaint himself fully with the history, 

 customs, and habits of the Indians, Ladinos, and 

 whites in the western part of the country, where 

 he resided. The results of his studies of the Indian 

 antiquities and languages he published in a pre- 

 vious work, reserving for his ' Guatemala ' the 

 recital of his travels, which, from Guatemala City, 

 extended over the east and south also, the politi- 

 cal history, statistics, mode of life of the inhabit- 

 ants, and general remarks upon the country. The 

 numerous shortcomings and barbaric customs of 

 the population do not excite in the writer a spirit 

 of rancor, implacable hatred, or justifiable irony ; 

 for in most instances he simply presents to the 

 reader, in frank and unmistakable terms, what he 

 has seen and heard, and then leaves it to him to 

 judge for himself. The tyrannic mode of ruling 

 inaugurated by Barrios, the late president, forms 

 a chapter too interesting to be skipped over. 



LETTERS TO THE EDITOR. 



♦** Correspondents are requested to be as brief as possible. The 

 writer's name is in all cases required as proof of good faith. 



3arometer exposure. 



Mr. H. Helm Clayton's interesting letter on the 

 above topic (Science, vol. vii. p. 484) is not quite so 

 satisfactory as his previous communication on ther- 

 mometer exposures. He seems to think that " the 

 facts all suggest that the wind, in blowing by at 

 right angles to the cracks and crevices in the build- 

 ing, produces a mechanical effect, which tends to 

 draw the air out of the building, and decrease the 

 pressure inside." 



Until it is incontestably established by observation 

 that such fluctuations in the height of the barometer 

 as he cites are peculiar to indoor barographs, it 

 seems to me quite premature to ascribe them to the 

 rarefaction of the air within the building. It cer- 

 tainly would be more satisfactory to the physicist, 

 had Mr. Clayton made comparisons of the simul- 

 taneous indications of indoor and outdoor barographs. 

 The observed facts are, that fluctuations of wind- 

 velocity correspond with fluctuations of air-pressure. 

 In some cases it may be difficult to decide which is 

 cause, and which is effect. Certainly, in ordinary 

 cases, the alteration of air-pressure is the cause, 

 and wind is the effect. But if, in certain cases, it 

 can be shown that indoor barometers are differently 

 affected from outdoor ones, there would be rational 

 grounds for reversing the usual relation of cause and 

 effect. If such is actually the case, it certainly is an 

 important item in barometric records. 



John LeConte. 



Berkeley, Cal., June 8. 



Amblystoma and Gordius. 



Eecently a fine specimen of Amblystoma mavor- 

 tium, presented me by Professor Sedgwick, was seen 

 to be greatly distressed in its left fore-arm. The 

 arm was swollen to its utmost ; and, holding it out 

 at right angles to the body, the ' salamander ' seemed 

 quite unable to use either arm or fingers. Enlarge- 

 ment of a small pore, in a prominence near the base 

 of the little finger, behind the carpals, disclosed the 

 cause of the trouble in a robust hair-worm a little 

 less than five inches in length and nearly one- 

 twentieth of an inch in diameter. Posteriorly two- 

 thirds of the worm's body was of a light pink or 

 flesh color ; in front of this it was darker, except 

 about three-quarters of an inch at the head, where 

 it was almost white. The worm was coiled among 

 the muscles of the fore-arm, and did not appear to 

 have wrought them any injury, the member in a 

 few days being as useful as its fellow. 



Submitted to Dr. Fewkes, the parasite was pro- 

 nounced an undetermined species of Gordius. 



S. Garman. 



Mus. comp. zool., June 10. 



Penetrating-power of arrows. 



I notice in Science for June 11 a short letter con- 

 cerning the penetrating- force of arrows. 



I have made the following experiment with a 

 Chinese bow and Japanese arrows : length of bow 

 unstrung 5 feet 11 inches ; length of string 5 feet 8 

 inches ; length of arrow do inches, weight of same 



ounces ; height of feathers f of an inch, length of 

 same 4 inches. 



The bow has a strength of 110 pounds when the 

 string is pulled back 34 inches : it is made of whale- 

 bone and bamboo cut in long strips and glued to- 

 gether. 



At 50 yards the entire arrow passes through au 

 inch plank of clear pine wood. At the same dis- 

 tance, with oak of the same thickness instead of 

 pine, the board is penetrated by the head of the 

 arrow, but the shaft is shattered to small pieces. 

 With a live pigeon at 20 yards, hit anywhere, the 

 entire arrow passes through intact. 



L. O. Kellogg. 



Oswego, N.Y., June 12. 



