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THE POPULAR SCIENCE MONTHLY. 



becomes actually incorporated with its sub- 

 stance. After tbis burning process, it only 

 remains for the different pieces to be united 

 with the grooved leaden framework which 

 binds the whole together. The places 

 where the leads join are then carefully 

 soldered together, and nothing remains but 

 to thoroughly work over the whole surface 

 with a thick kind of cement, which fills up 

 any interstices between the glass and lead, 

 and renders the whole panel perfectly water- 

 tight and weather-proof. " 



Assimilative Power of Plants. — In a paper 

 read before the Dublin Royal Society, Dr. 

 C. A. Cameron states the result of a prelimi- 

 nary experiment made by him to determine 

 the possibility of substituting for some of 

 the elements in plants other elements of the 

 same atomicity. A sod was taken from a 

 field in which a crop of the so-called artifi- 

 cial grasses (which are chiefly leguminous 

 plants, and not grasses at all) was just peep- 

 ing over ground. It was placed in a box, 

 and one half of the plants were watered 

 twice a week with a weak solution of potas- 

 sium selenate. The total quantity of potas- 

 sium selenate applied to the plants during 

 four weeks amounted to twenty grammes. 

 The result showed that selenic acid, at least 

 when applied in small quantity, does not 

 injure plants. Secondly, it was found that 

 selenic acid had been absorbed by the 

 plants. To determine this point, the plants 

 were partially dried and boiled in strong 

 nitric acid until thoroughly destroyed. The 

 solution was evaporated to dryness, and the 

 residue was treated with dilute hydrochloric 

 acid, which dissolved it nearly completely. 

 The solution was concentrated and mixed 

 with a saturated solution of sulphurous acid, 

 whereupon the liquid assumed at once a 

 deep, blood-red color, from the separation 

 of selenium. The plants had been carefully 

 washed before being dried. In concluding 

 his paper. Dr. Cameron writes as follows: 

 " I think this experiment proves that selenic 

 acid is not injurious to plants when used in 

 small quantity, and that the acid is taken 

 up and retained by plants, or at least by 

 certain varieties of plants. The experiment, 

 however, did not prove whether or not there 

 was a partial replacement of sulphur triox- 

 ide by selenium trioxide or of sulphur by 

 selenium. Having lately become possessed 



of large quantities of selenium compounds, 

 I propose to grow plants in soil or water 

 free from sulphur in any form, but supplied 

 with potassium and ammonia selenates. 

 Should the results of this proposed experi- 

 ment prove interesting, I shall do myself 

 the honor of submitting them to the so- 

 ciety." 



Honey-making in the United States. — 



The annual production of honey in this 

 country is estimated at about 35,000,000 

 pounds, and the business of bee-keeping is 

 being rapidly systematized. One firm of 

 wholesale grocers in New York keeps as 

 many as 12,000 swarms ; other keepers 

 have often from 3,500 to 5,000 swarms. 

 Arrangements are made with farmers and 

 owners of orchards to allow an apiary of a 

 certain number of swarms to be placed in 

 their grounds. At the distance of three or 

 four miles another apiary is placed with 

 another fanner, and so on. For this accom- 

 modation the bee-keepers pay either in 

 money or in shares. It is estimated that on 

 an average an acre will support twenty-five 

 swarms, yielding fifty pounds of honey each. 

 The apiaries are cared for by men in the 

 employ of the bee-owners. Many ingenious 

 contrivances have been introduced for the 

 purpose of saving the labor of the bees and 

 the keepers. About ten years ago a Ger- 

 man suggested that thin, corrugated sheets 

 of wax, which he called " artificial tablets," 

 should be provided for the bees to make 

 their comb from. These, however, did not 

 come into general use ; but a few years ago 

 Mr. W. M. Hoge effected an improvement 

 by starting the side-walls of the cells. When 

 these "foundations," as they are called, 

 were presented to the bees, the intelligent 

 little creatures at once took advantage of 

 them, and extended the side-walls so as to 

 form the regular hexagonal cell. The ma- 

 chine by which the impression is made on 

 both sides of the wax is very simple, and 

 somewhat resembles a clothes-wringing ma- 

 chine, only the iron rollers are studded with 

 little hexagonal-headed pins just the size of 

 the section of a cell, so that, when the thin 

 sheet of wax is pressed up between the pegs 

 to the height of about one sixteenth of 

 an inch, it offers a substance for the con- 

 struction of the cell-walls. Another re- 

 markable adaptation of machinery is afford- 



