7 68 



THE POPULAR SCIENCE MONTHLY. 



The Dean of Carlisle, Dr. Close, having 

 made a violent attack on the practice of 

 vivisection, denouncing it as a crime in the 

 sight of that God " who careth for the spar- 

 rows," the Lancet very wittily retorts by 

 quoting another Scriptural passage which 

 the anti-vivisectionists are too prone to over- 

 look : " Men are of more value than many 

 sparrows." 



Experiments made by Astasheffsky go 

 to prove that the saliva of the rat possesses 

 very strong diastatic activity in other 

 words, very rapidly converts starch into 

 glucose; and that, as a general rule, the 

 saliva of the rodents holds the foremost 

 place as regards the mammalia ; next comes 

 that of the carnivora ; and lastly that of the 

 herbivora the latter being decidedly the 

 weakest of the three. 



A writer in the School Journal would 

 have all school chairs or seats on their front 

 edge not more than one-quarter the height 

 of the occupant, or of such a height that 

 when sitting well back the heels of the sit- 

 ter may touch the floor at a distance in 

 front of the seat equal to the height of the 

 seat. This it is claimed allows the point of 

 support to be changed for the sake of com- 

 fort, and yet allows no unhealthy pressure. 

 The width of the seat should equal its height ; 

 the slant should be about three-quarters 

 of an inch to the foot ; the surface should 

 be flat. The back should be not less than 

 one-tenth in excess of the height of the 

 seat, so as to give full support to the shoul- 

 der-blades ; it should slant about two and a 

 half inches to the foot. The desk at the edge 

 next the sittershouldbe five-thirds the height 

 of the highest edge of the seat ; its slant 

 should be about one inch to the foot ; its 

 lower edge should stand directly above the 

 front edge of the seat. 



TnE cremation of the dead on battle- 

 fields is strongly advocated by Mr. William 

 Ea6sie in an address to a sanitary congress 

 in England. He is confident that by means 

 of portable crematories he could reduce to 

 ashes 10,000 bodies in as many minutes of 

 time. Interment of bodies by thousands 

 must of necessity pollute the springs and 

 contaminate the air. 



The building recently opened and dedi- 

 cated in New York City for the use of the 

 American Museum of Natural History con- 

 sists of three stories, besides the basement 

 and attic. These three stories constitute 

 three halls, each 60 feet wide and 1*70 feet 

 long, access being had by stairways in a 

 tower at one end. The present building 

 forms only a small part of a vast struct- 

 ure which it is designed to erect. The 

 ground-plan of the future Museum may 



be described as a cross inclosed within a 

 square. The portion of the structure now 

 completed will form the northern end of 

 the cross. The ground to be covered and 

 inclosed by the buildings will be 850 feet in 

 length by 650 feet in width. 



A roof of zinc-coated sheet-iron, says 

 the Polytechnic Review, does not wear out 

 from oxidation, and does not crumble as 

 does sheet-tin from the repeated contraction 

 and expansion produced by changes of tem- 

 perature. In Vienna and in Prague the 

 manufacture of this roofing material is a 

 growing industry. 



The year 1877 showed a very consider- 

 able increase in the production of cocoon- 

 silk in France over the preceding year, viz. : 

 in 1876 the product was 2,396,000 kilo- 

 grammes, but last year it was 6,783,000 

 kilogrammes. But this industry has yet to 

 struggle hard if it is to attain in France 

 its former condition, when the annual 

 yield of cocoons was over 25,000,000 kilo- 

 grammes. 



The leather covers of books in public 

 libraries suffer very much from the action 

 of the combustion-products of coal-gas. Ac- 

 cording to Prof. A. H. Church, vellum ap- 

 pears to be unaffected by this cause ; but 

 calf is much injured, and russia still more 

 so. Most damage is done to the books in 

 the upper shelves of a library, where the 

 heated products of combustion are mostly 

 condensed and absorbed. The sulphur of 

 the gas is the principal cause of its destruc- 

 tive influence. Analysis of watery extract 

 of leather injured by this cause showed that 

 sulphuric acid, free and combined, was pres- 

 ent in the proportion of 8.42 per cent. 



The truth of the germ-theory of disease 

 would seem to be demonstrated, at least 

 with regard to one disease splenic fever 

 by the researches of Dr. Koch. In cases of 

 this disease, there accumulates in the blood 

 and tissues, but especially in the spleen, a 

 peculiar kind of bacteria Bacillus anthra- 

 cis. On inoculating animals with fluid con- 

 taining either the bacilli themselves or their 

 spores, Dr. Koch produced all the phenom- 

 ena of splenic fever. 



An Italian chemist, Paesi, proposes to 

 substitute, for the tannin-bath in the manu- 

 facture of leather, a solution, in water, of 

 perchloride of iron and common salt. Hides 

 may be tanned, according to this process, 

 in from four to six months. Moreover, the 

 perchloride of iron, being a powerful disin- 

 fectant, does away with many objectionable 

 features of the tanning business as hitherto 

 conducted. 



