P OP ULAR MIS CELL ANY 



379 



side, seems, as it issues from the doors and 

 windows of the stone houses, to pause in 

 mid-air like a droning bee. Then scores of 

 busy figures repair with their water-vessels 

 to the verge of the steep bluffs, and disap- 

 pear in the crevices of the rocks below." 



How Monkeys dislike Siiakes. That 

 monkeys, like man, have a peculiar instinc- 

 tive abhorrence of snakes, is shown by an ex- 

 periment made in the Philadelphia Zoologi- 

 cal Garden by Mr. Arthur E. Brown, and 

 recorded in the American Naturalist. Mr. 

 Brown having wrapped a dead snake in pa- 

 per, set the package on the floor of a cage 

 containing forty or fifty monkeys. It was 

 instantly spied by a female cynocephalus, 

 who quickly seized the paper and dragged 

 it away with her. Soon the paper unfolded 

 and the snake slipped partly out. On see- 

 ing what the package contained, the cyno- 

 cephalus instantly dropped it and sheered 

 off. The other monkeys now cautiously ap- 

 proached the dead snake, but all were care- 

 ful not to come too near, with the exception 

 of one, a large macaque, who would make 

 an occasional snatch at the paper, as though 

 to see whether the dreaded animal were real- 

 ly dead. A pull on a string attached to the 

 tail of the snake, causing it to stir, sent the 

 inquisitive monkeys scampering away, but 

 they would again return, ever keeping at a 

 respectful distance. The dead snake was 

 then successively introduced into cages oc- 

 cupied by animals of other orders car- 

 nivores, rodents, ungulates, etc. but none 

 of them paid it any special attention except 

 one peccary, which, finding that it was dead, 

 seemed disposed to eat it. The author ob- 

 served in a deaf and dumb lady the ex- 

 pression of the same emotions and feelings, 

 on beholding serpents, which had been ex- 

 hibited by the monkeys. There were the 

 same fear, the same attraction and repul- 

 sion ; and after watching for a long time, 

 with an expression of intense disgust, a cage 

 of boas, she was led away by her friends, 

 protesting that she wanted to stay. 



Discoloration of Brick Walls. Brick 

 buildings, in the neighborhood of New York, 

 are often seen disfigured by streaks and 

 patches of white ; but it is in Philadelphia 

 that the evil is most noticeable. There 

 these white incrustations are very general 



on brick house-fronts, and the study of their 

 causes and their remedy has for some time 

 engaged the attention of builders. Mr. Wil- 

 liam Trautwine is, so far as we know, the 

 first who has attempted a thorough, scien- 

 tific investigation of the subject ; and his ob- 

 servations, published in the Journal of the 

 Franklin Institute, are eminently worthy of 

 the attention of architects in localities where 

 this disfiguration makes its appearance. 

 The evil, he says, is most noticeable in dry 

 weather on parts of walls subjected to damp- 

 ness, and on entire walls after rain-storms 

 have soaked them. The white coating is de- 

 rived primarily from both the bricks and the 

 mortar. In some instances it undoubtedly 

 comes from the bricks ; here the white sub- 

 stance is dissolved by moisture from the 

 bricks even before they are built into the 

 houses. The author has found it in bricks 

 just from the kiln. It has a peculiar taste 

 that of sulphate of magnesia ; but besides 

 this salt the bricks also contain sulphate of 

 lime. The author's theory is that the sili- 

 cates of magnesia and lime in the bricks are 

 converted into the sulphates by the sulphuric 

 acid evolved from the sulphide of iron and 

 iron pyrites contained in the coal which is 

 employed in the kilns. Now, sulphate of 

 magnesia effloresces in dry air, and sulphate 

 of lime is dissolved by moisture and appears 

 on the surface of the bricks. Hence, plain- 

 ly, one mode of preventing the incrustation 

 is the employment only of wood or of coke 

 free from sulphur in the kilns at least this 

 might be done in the manufacture of pressed 

 brick for house-fronts. As for the incrusta- 

 tions having their origin in the mortar, the 

 author remarks that sulphate of magnesia 

 is largely produced by the decomposition of 

 mortar. His observations on this head have 

 special application to Philadelphia and its 

 vicinity, where most of the lime used in 

 building is from magnesian limestone. The 

 resulting mixture of limestone and magne- 

 sia, when slaked and made into mortar, is 

 very susceptible to the influence of sulphur- 

 ous fumes in the atmosphere, which pro- 

 duce in the mortar sulphates of lime and 

 magnesia. The great solubility of sulphate 

 of magnesia facilitates its diffusion ; sul- 

 phate of lime is comparatively insoluble, 

 and does not cause so much disfigurement. 

 Of course, mortar made with lime from 

 magnesian limestone quickly decomposes, 



