POPULAR MISCELLANY. 



507 



eye, requiring more exertion of the muscles 

 that govern the movements of the eye. The 

 distance between the hues should be about 

 one-eighth inch ; nearer than this is apt to 

 be confusing, farther apart is also confusing. 

 Heavy-faced type is preferable to light- 

 faced. An almost imperceptible yellow tint 

 in the paper, "natural tint," is very desi- 

 rable ; pure white paper, especially if it has 

 a metallic lustre with bluish tinge, should 

 not be employed. The paper should be 

 thick enough not to be transparent, should 

 have a close, fine texture, and be free from 

 sponginess. To the third question whether 

 too long and constrained attention to one ob- 

 ject, without rest or variety, will cause eye- 

 disease? Dr. Loring replies affirmatively, 

 and assigns the physiological reasons. Fi- 

 nally, he was asked whether the angle at 

 which light strikes the eye is important ? 

 He replies that the light should not come 

 directly in front; neither should it come 

 from directly behind. It should not come 

 from the right side, because, in writing, the 

 shadow of the hand falls across the page ; 

 and a moving shadow over a lighted sur- 

 face not only reduces the quantity of light 

 and leads to a stooping position, but it is 

 also more annoying to the eye than a uni- 

 form reduction in the illumination of even 

 a greater degree. The best direction for 

 the light to come is from the left-hand side, 

 and from rather above than below the level 

 of the hand. 



High Temperatures and Bowel-Com- 

 plaints. Dr. N. S. Davis, in a " Report on 

 Clinical and Meteorological Records " com- 

 municated to the American Medical Asso- 

 ciation, an abstract of which we find in the 

 Medical Record, reaches the conclusion that 

 the bowel affections, so characteristic of 

 this temperate climate, begin invariably 

 with the first week of continuous high tem- 

 perature, and that every subsequent occur- 

 rence of several days and nights of continu- 

 ous high temperature causes new attacks 

 to be increased in number throughout the 

 month of July, less in August, and still less 

 in September ; that it is not simply the 

 extreme of heat, but its duration, which 

 determines the number of attacks ; that 

 this continuous high heat, to be efficient in 

 producing these affections, must follow a 



protracted season of cold ; and that, if we 

 compare these deductions directly with sta- 

 tistics of mortality, we shall find them to 

 conform in every particular in that the 

 higli rate of mortality follows exactly the 

 same line. That fact was regarded as one 

 of great importance in connection with sani- 

 tary measures which were to be adopted for 

 the protection of life in infants ; preventive 

 measures must strike with the first week of 

 consecutive high temperature. These con- 

 clusions were corroborated by quotations 

 from mortality-tables. 



Blanniial Value of Spent Tan and Saw- 

 dust. From careful analyses of spent tans 

 and dyewoods and other similar waste ma- 

 terials. Prof. F. H. Storer, of the Bussy In- 

 stitution, reaches the general conclusion 

 that they contain but a very small propor- 

 tion of fertilizing substances, and that prac- 

 tically, whether they be fresh or rotten, 

 they have very little value as m.mure. Of 

 fresh sawdust, even that from hard woods, 

 he says that it can hardly be considered 

 an economical manure ; it is far inferior, 

 for compost, to peat. But, curiously enough, 

 the chemical evidence goes to show that it 

 is for feeding animals rather than for feed- 

 ing plants that sawdust might be put to 

 use. Fresh sawdust, even that of pine- 

 trees, can be used with advantage as fodder 

 in times of dearth. Twigs and leaves, as 

 the clippings of vines and hedges, or bushes 

 mown in pastures, are undoubtedly valuable 

 both as manure and forage. Autumn leaves 

 and the rakings of woodland, which consist 

 for the most part of leaves that have not 

 only fallen, but have bisen bleached by 

 rains, may be classed as somewhat inferior 

 to straw. 



Wearing Qualities of Alumininm. The 



comparative resistance of aluminium to 

 change of color and wear, when brought into 

 daily use, has been made the subject of ob- 

 servation by Dr. C. Winklcr,of Freiberg, who 

 finds, according to the Polytechnic Revieio, 

 that it is inferior to silver in retaining color 

 and lustre, being about on a par with Ger- 

 man-silver in these respects ; while it wears 

 away more rapidly than silver, but less so 

 than German-silver. Spoons made of all 

 three materials, each having exactly the 



