574 



THE POPULAR SCIENCE MONTHLY. 



ever tends to obstruct transpiration promotes 

 the accumulation of impurities. For this 

 reason, even paint, though it may be intrin- 

 sically harmless, is objectionable. Paper is 

 positively objectionable, because itself col- 

 lects impurities and retains them ; the sub- 

 stances with which it is prepared and deco- 

 rated do the same ; and the paste with which 

 it is attached responds to all dampness and 

 atmospheric influences, and readily becomes 

 moldy. Kalsomine is faulty, because it is 

 prepared with glue, and that, besides stop- 

 ping the pores in the plastering (or " strang- 

 ling the wall "), is liable to decay. No wall 

 coating can be more healthful than a lime- 

 wash. But, since that is inconvenient on ac- 

 count of its rubbing off, an excellent sub- 

 stitute is recommended by Mr. M. B. Church 

 in calcined plaster of Paris, which hardens 

 at once, forming a fixed shell of perfect 

 porosity. 



NOTES. 



A Correction. — By a slip of the pen 

 which also escaped notice in the proof-read- 

 ing, Prof. Weismann is made to say twice in 

 the second paragraph of page 357 of our 

 July number " cerebellum " where " cere- 

 brum " was intended. Read — " if, again, we 

 were able to remove all the other parts of 

 the cerebrum," etc., and " with the rest of 

 the cerebrum was taken, etc." 



The meeting of the British Association 

 for 1890 will be held at Leeds, September 

 3d to 10th, under the presidency of Sir 

 Frederick Abel. The sectional presidents 

 will be : A, Dr. J. W. L. Glaisher ; B, Prof. 

 T. E. Thorpe; C, Prof. A. H. Green; D, 

 Prof. A. Milnes Marshall ; E, Sir R. Lam- 

 bert Playfair ; F, Prof. Alfred Marshall ; G, 

 Captain A. Noble ; H, Dr. John Evans. Even- 

 ing addresses will be given by Mr. E. B. 

 Poulton on Mimicry ; Prof. C. Vernon Boys 

 on Quartz Fibers and their Applications ; 

 and Prof. Perry will lecture to the working 

 classes on Spinning Tops. 



A new food is described in the Kew Bul- 

 letin as used by the poorer classes in north- 

 ern India. It is called phog, and is made 

 from the flowers of the plant Calligonum 

 polygonoides. They are eaten mixed with 

 flour, or separately with salt and condiments 

 They are rich in nitrogenous compounds, and 

 somewhat resemble the seeds of the edible 

 amaranths and buckwheats, only that in 

 them sugar replaces starch. 



A visible illustration of the figures pro- 

 duced by sound-waves has been devised by 

 Mrs. Watts Hughes, in what she calls " voice- 



figures." They are practically Chladni's 

 figures, produced in a viscid medium. Semi- 

 fluid paste is spread over an elastic mem- 

 brane stretched over the mouth of a receiver. 

 A single note sung into the receiver throws 

 the paste into waves and curves. The pat- 

 terns formed are photographed immediately 

 after production, or are transferred as water- 

 color impressions while the membrane is still 

 vibrating. Perhaps the most interesting 

 figures are the " daisy forms," in which " the 

 number of petals increases as the pitch of 

 the note that produces them rises." 



Mr. Albert Koecele, who was dispatched 

 to Australia under the direction of the En- 

 tomologist of the Agricultural Department to 

 obtain natural enemies of the " fluted scale " 

 of the orange (leery a purchasi), brought 

 home an insect, the cardinal vedalia, which 

 has proved very efficient. It has already 

 multiplied to such an extent as to rid several 

 groves from Icerya, and is looked upon as 

 promising immunity in the near future for 

 the entire State of California. In fact, Dr. 

 Riley fears that it will do its work so well 

 as to leave no field for other insects which 

 Mr. Koebele procured, and which it is de- 

 sirable to cultivate for the sake of having a 

 variety. 



In a paper in the Connecticut Pharma- 

 ceutical Association, Mr. D. G. Stoughton 

 appears to have arrived, by a way of his 

 own, at the conception of the identity of 

 electricity with the other physical forces, 

 heat and light, now demonstrated by Mr. 

 Hertz's experiments. He regards them as 

 resultants of the obstruction of ether motion 

 by matter. Molecular motion, intense within 

 the sun, is supposed to be transformed at 

 the confines of the gaseous envelope sur- 

 rounding that body into ether motion, which, 

 passing through the ninety million miles of 

 ether to the confines of our atmosphere, is 

 obstructed by the molecules of atmosphere, 

 and gives rise, according to the measure 

 of the obstruction, to electricity, light, and 

 heat. 



Holmgren's test for color-blindness is 

 the one recommended by those who have 

 given the subject most attention. There 

 are three parts to the test, which consist in 

 picking out from a lot of wools all those 

 skeins that match given ones in color. A 

 pale green is the test-color first used, then a 

 dilute purple, and finally a bright red. The 

 person is not required to name any colors, as 

 this is a different matter from distinguishing 

 them. 



A writer in Le Monde de la Science et 

 de l'Industrie recommends, as an excellent 

 insoluble plastic material, a mixture of 

 cheese or casein or albumen and lime, well 

 worked up. It is insoluble in hot water. 

 Artistic effects may be obtained by molding, 

 and it is easily colored. 



