SCIENCE. 



[Vol. XVII. No 427 



NOTES AND NEWS. 



The excursion committee of the Appalachian Mountain Club, 

 Boston, presents the following preliminai-}' progTamme for the 1891 

 excursions, subject to possible changes: Saturday, April 18, may- 

 flower vralk, Marshfield ; May 9, Mav walk, Andover, Mass, ; May 

 30, Mount Wachusett; June 17, laurel excursion to either Milford 

 or Mount Vernon. N.H. ; about July 1, field meeting at the Cats- 

 kill Mountains, N.Y. ; Monday, Sept. 7 (Labor Day), Bristol, 

 N.H. It is hoped that a camping party to Moosehead Lake may 

 be arranged in August. Members who desire to join the party 

 are requested to notify the chairman of the special committee 

 before July 35. The autumn excursion may possibly be to Mount 

 Choeorua the latter part of September, 



— Bulletin No. 72 of the Michigan Agricultural Experiment 

 Station is by W. J. Beal, and is entitled ' ' Six Worst Weeds, " 

 Mr. Beal states that some of our most troublesome weeds are 

 natives of the neighborhoods in which they are found, but most 

 of them have been introduced from other portions of our own 

 country or from foreign countries. The seeds of most weeds find 

 their way on to a farm nicely mixed with seeds of grasses, grains, 

 and clovers, which are drilled in or sowed broadcast on fertile 

 soil, where they are afforded an excellent opportunity to grow 

 and multiply. In some instances weeds are introduced as a part 

 of the packing or straw employed to protect castings, marble, 

 crockery, or fruit-trees. Such foreign packing should always be 

 burned at once. By these processes above noticed, the older the 

 country, the more troublesome weeds it will have, as every new 

 intruder usually comes to stay. In most cases a weed becomes 

 well established before it is discovered; and the inquiry comes, 

 "What is it, and how can I get rid of it?" Enclosed in the 

 bulletin were samples of seeds of six sorts which have a bad 

 reputation, and it will be best to watch them. Most of them are 

 already pretty well known by some of our farmers. They are not 

 indigenous, but have all been introduced from Europe. The 

 following rules are worth observing: 1. Carefully examine seeds 

 before sowing, and see that they are clean, and thus prevent the 

 introduction of weeds; 2. Keep a sharp lookout, and exterminate 

 the few first intruders before they spread themselves; 3. Usually, 

 as in all the six cases referred to, perhaps excepting the Canada 

 thistle, one or more so-called hoed crops, like corn, potatoes, or 

 beans, most thoroughly tended throughout a single growing 

 season, or for two seasons in succession, will be a good practice. 

 There is no royal way in which to kill weeds. 



— To find a paint of lasting qualities, which will prevent the 

 corrosion of iron due to atraosjiheric agencies, is a problem with 

 which engineers have dealt earnestly for many years. Until within 

 quite recent years, little has been known in this country of the 

 valuable properties of asphalt, and to many they are still unknown. 

 In the popular mind it is often confused with certain coal-tar 

 products, which, though similar in appearance, differ essentially 

 from asphalt in character. Asphalt oils are of a non-volatile 

 nature, and are therefore permanent, while, on the other hand, 

 coal-tar and linseed oils are volatile, and therefore non-permanent. 

 Herein lies the secret of the paint problem, says The Railroad and 

 Engineering Journal for April. In order to prevent rust, some 

 substance must be ufed as a coating for the iron which is im- 

 pervious to air and moisture; and it is of equal importance, that 

 it may remain impervious, that it should be unaffected by the 

 heat of the sim and by exjjosure to the air. It is claimed that 

 there is no other substance in nature which so nearly complies 

 with these severe requirements as asphalt. The so-called asphalt 

 paints which have been commonly used in the past are such only 

 In name. They contain, at best, but a very small per cent of 

 asphalt, which is incorporated in the form of a pigment, and 

 which serves no valuable purpose. Asphalt, on the contrary, 

 should be the main constituent, since the virtue of such a paint 

 depends upon the presence of the permanent asphalt oils. When 

 these so-called asphalt paints are made in light colors, durability 

 becomes subservient to ornamentation. The virtues sought in 

 asphalt are lost by substituting for it the necessarily large quan- 

 tity of light-colored pigment essential in counteracting the natural 

 dark color of the asphalt. 



— The question of the use of special fertilizers under glass is 

 becoming one of great importance, and is attracting much at- 

 tention among practical gardeners and scientific men. Even the 

 best and most skilled gardeners sometimes find that their soil, 

 made up after the best formulas, fails to give the results expected. 

 The plant-food seems to be unavailable, or the plant lacks the 

 vigor to make use of it, and something more active is needed to 

 give it a start. To determine what special fertilizers will give 

 the best results applied to crops under glass, a series of ex- 

 Ijeriments wex-e started in the winter of 1888-89, at the Massachu- 

 setts Agricultural College, under the direction of Samuel T. May- 

 nard of the Division of Horticulture, the results of which are 

 deemed of sufficient value for publication, although a longer 

 series of tests may somewhat modify the results thus far obtained. 

 In it was found, that, of the 'nitrates, the nitrate of potash gave 

 the best results, but that the sulphate of ammonia gave better re- 

 sults than either, especially in the production of a foliage crop 

 Of the potash salts, the sulphates gave better results than the 

 muriate. Bone-black showed a marked effect in increasing the 

 number of blossoms. 



— The director of the Connecticut Agricultural Experiment 

 Station, New Haven, Conn , calls the attention of dairymen to a 

 method of determining fat in milk devised by Dr. Babcock of the 

 Wisconsin Station. Its merits are, that it is rapid; that both the 

 milk and the fat are measured, so that all weighing is dispensed 

 with; and that it is very accurate. It furnishes, he thinks, the 

 most rapid and accurate means of testing milk of individual cows 

 or herds. The apparatus is in dail3' use at the station. Twenty- 

 three cows are under experiment, and separate fat determinations 

 are made daily in the morning and night milk of each cow; the 

 whole, including the cleaning of the apparatus, being accomplished 

 in two hours by two persons. A considerable saving of time will 

 be secured when power is used for driving the centrifuge. With 

 this aid, a young man or woman could probably do the whole 

 easily in from three to four hours. 



— A correspondent of the PaH Mall Gazette writes, "I recently 

 witnessed the following little incident on the Thames, near 

 Twickenham, when the river was full of land-water, and there- 

 fore very swift and dangerous. Two dogs — one a large animal, 

 the other a little terrier — were enjoying a swim near the bank, 

 but soon the little one was carried out some distance, and was 

 unable to get to shore. By this time the big dog had regained 

 the shore, and, seeing what was happening to his companion, be 

 gan running backwards and forwards in the most excited manner, 

 at the same time whimpering and barkin.g, arid evidently not 

 knowing for the moment what to do. The terrier was fast losing 

 strength, and, although swimming hard, was being rapidly carried 

 down stream. The big dog could contain himself no longer. 

 Running some yards ahead of his struggling frieml, he plunged 

 into the water and swam vigorously straight out until he got in a 

 line with the little head just appearing behind him. Then he 

 allowed himself to be carried down, tail first, until he got next to 

 the terrier, this being accomplished in the cleverest manner, and 

 began to swim hard, gradually pushing the little one nearer and 

 nearer to the shore, which was gained after a most exciting time. 

 The fact of this canine hero going so far ahead to allow for the 

 strong current, and the judgment shown in getting alongside, and 

 then the pushing, certainly seemed to me to betoken instinct of a 

 very high order '' 



— An important communication upon the color and absorption 

 spectrum of liquefied oxygen is made by M. Olszewski to a Ger- 

 man periodical, and a brief abstract is published in Nature of 

 March ^6. Liquid oxygen has hitherto been described as a color- 

 less liquid. In thin layers it certainly appears to be colorless; but 

 M. Olszewski, in the course of his investifiation of the absorption 

 spectrum, has obtained a sufficient quantity of the liquid to form 

 a layer thirty millimetres thick, and makes the somewhat unex- 

 pected and very impoitant discovery that it possesses a bright 

 blue color resembling that of the sky. Great precautions were 

 taken to insure the purity of the oxygen employed, the absence of 

 ozone, which in the liquid state possesses a deep-blue color, being 

 especially ascertained. Carbon dioxide, chlorine, and water -vapor 



