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THE POPULAR SCIENCE MONTHLY. 



At the recent scientific meeting in Du- 

 buque, Miss Swain read a paper entitled 

 " Why we differ, or the Law of Variety." 

 In regard to the sexes, she took the ground 

 of Luke Owen Pike, that differences are 

 due to the different proportions of the same 

 qualities, men and women differing not in 

 elemental composition, but in excess or de- 

 fect of common properties. She is said to 

 be the first lady who has ever addressed 

 this Association, but she is certainly not the 

 first who has contributed to its proceedings. 

 Mrs. Elisha Foote prepared a paper, the re- 

 sult of her experimental investigations on 

 heat, which was read at the meeting in Al- 

 bany in 1856. 



It is stated by Jean that our ordinary 

 soaps are so adulterated, under pretence of 

 cheapness, that little of soap remains but 

 the name. The chief adulterant is resin, 

 which combines with the potash or soda in 

 place of the 50 or 60 per cent, of fatty 

 acid that should be present. These alka- 

 line resinates impart to the soap the power 

 of lathering copiously, and they even sapon- 

 ify in water containing gypsum. These 

 good properties are, however, counterbal- 

 anced by serious disadvantages. If resin- 

 ous soaps are used in fulling cloth, they 

 produce blemishes. They also impart to 

 worsted stuffs a peculiar greasy lustre, and 

 wool scoured with these takes the mordants 

 and dyes unequally. 



Woodman reported at Dubuque on an- 

 cient mounds. He says that these and 

 other old earthworks are far more abun- 

 dant than is generally supposed. The city of 

 Dubuque, he states, is full of them, although 

 they have been extensively obliterated with- 

 out being recoguized. They are almost in- 

 variably fifteen paces apart from centre to 

 centre, the smaller ones being from two to 

 two and a half feet high, and about twenty 

 feet in diameter, and are arranged in straight 

 or slightly-curved lines. Some mounds con- 

 tain skeletons, and were probably designed 

 for tombs, while other and larger mounds 

 are supposed to have been residences of the 

 ancient inhabitants of the continent. 



Dr. G. W. Hough has introduced a print- 

 ing-chronograph into the Dudley Observ- 

 atory, which has been in operation a year 

 and a half. Observations have been made 

 in that time on 10,000 stars, and the 

 number of records taken and printed 

 amount to 150,000. The chronograph is 

 an instrument for noting precisely the as- 

 tromical time at which the observation of a 

 heavenly body is made. The first chrono- 

 graph was a Morse register. Dr. Hough 

 has improved upon this, and says that he 

 can do twice as much work as formerly in 

 the laboratory, by the use of the invention. 



A paper from Prof. E. W. Hilgard, State 

 Geologist of Mississippi, was contributed on 

 " Soil Analyses and their Utility." Prof. 

 Mapes a few years ago made a great deal of 

 noise about soil analysis, and was accused 

 of " running it into the ground." Prof. 

 Johnson, of Yale, showed that there was a 

 good deal of humbug about so-called soil- 

 analyses, and pointed out the exaggerated 

 value that is commonly attributed to them. 

 But Prof. Hilgard has such faith in them 

 that he proposes to vary the usual routine 

 in State geological surveys by introducing 

 them, and he thus returns to the policy of 

 Emmons in conducting the New York State 

 Geological Survey. 



A new process, which has received the 

 name of Helio-Autographic Printing, has re- 

 cently been brought out in Paris. It is 

 said to enable the artist to make his own 

 designs and drawings, to print from them 

 on photographic paper, and reproduce the 

 same upon lithographic stone, so as to ob- 

 tain impressions of his own work in the 

 minutest detail, without the aid of the en- 

 graver, or lithographic draughtsman. 



According to Schmidt, an excellent rem- 

 edy against caterpillars consists in a dilute 

 solution (1 part in 500) of sulphide of potas- 

 sium, the infested tree being sprinkled with 

 this substance by means of a small hand- 

 syringe. This method has been used on a 

 large scale in France, and, it is said, with- 

 out any injury to vegetation. 



According to the Medical Times and. 

 Gazette, the cholera is gradually making its 

 way westward, having but recently entered 

 Prussia. The disease is of a mild type, 

 however, and spreads slowly. In Berlin it 

 first appeared in one of the most fashiona- 

 ble streets in the city, three cases occurring 

 nearly at the same time, in one and the 

 same house. 



Prof. Peirce exhibited at the Dubuque 

 meeting some interesting astronomical pho- 

 tographs and engravings prepared by Prof. 

 Winlock, of Harvard College. It appears, 

 by these charts, that Jupiter changes his 

 color even on successive nights. The rep- 

 resentations of sun-spots were said to be 

 very instructive, showing their connection 

 with the solar protuberances ; the draw- 

 ings of the latter indicate an unmistakable 

 atmosphere at an altitude of 100,000 

 miles. 



A red color has sometimes . been ob- 

 served in white lead, and has been formerly 

 attributed to the presence of silver. Ger- 

 man investigations have recently shown that 

 this is incorrect, and that the red tinge is 

 due to defects in manufacture. 



