July 26, 1895.] 



SCIENCE. 



Ill 



noted by other obsei'vers and myself. The 

 mass of Venus approaches nearer to that 

 of the earth than the mass of any other 

 planet, and it will probably not be very dif- 

 ferent from the earth in its temperature. 



In the case of the moon the temperature 

 is probably very low. Peal and others re- 

 gard it as glaciated. Langley says at full 

 jnoon the temperature is not above 0° 

 centigrade. I need not remind you that 

 the mass of the moon is very small. The 

 mass of Mars is only about one-ninth that 

 of the earth, and it may be on the whole a 

 colder world. The vast polar caps have 

 a great resemblance to snow ; they enlarge 

 during the winter and decrease during the 

 summer. The canals, about which so much 

 has been written, are just as likely to be 

 rents or fissures in ice fields, or vast ice 

 crystals on the surface of liquid, as to be 

 vegetation near artificial streams. 



Jupiter is the giant world, and if the 

 temperature increases with mass its heat 

 must be very great. Careful scrutiny sus- 

 tains this view ; no polar snow caps can 

 be seen; the belts and spots show so many 

 changes that the best observers regard the 

 planet as a very hot body. Proctor even 

 contended that it radiated heat to the sat- 

 ellites, and was in that respect an addi- 

 tional sun to them. 



This speculation is of great interest to 

 me and I would be pleased sometime to 

 continue the subject, but I think enough 

 has been said to show that it is not void of 

 interest, and that going outwards from the 

 Sun temperature seems to increase with 

 mass. I need scarcely remind you that the 

 mass of the Sun itself is vastly greater 

 than that of all the bodies of the sj^stem 

 combined, and that his heat is enormoxis. 



SCIENTIFIC JOURNALS. 

 AMERICAN CHEMICAL JOURNAL FOR JULY. 



The July number of the American Chem- 

 ical Journal contains an article by W. F. 



Edwards entitled ' Notes on Molecular and 

 Atomic Refractions.' He oflfered, sometime 

 ago, a new formula, --jjjj^, for molecular 

 refraction, and the present paper contains 

 the results of further research and com- 

 parisons of the results obtained by the use 

 of his formula with those obtained with the 

 formulse of Gladstone and Lorentz-Lorenz. 

 He has compared a number of cases of acids 

 and ethereal salt and has determined the 

 change caused by the addition of CHj, and 

 the numbers representing the atomic refrac- 

 tions of hydrogen, oxygen, nitrogen, chlo- 

 rine, bromine, iodine and sulphur, in terms 

 of his formula. 



By the use of his formula he can tell 

 whether the nitrogen is present in the triva- 

 lent or univalent condition ; but with the 

 others this is impossible. Although a great 

 number of observations are available the 

 results are not such as would render any 

 general conclusions possible in many cases. 

 Hite, and Orndorfif and Cameron, describe 

 the pieces of apparatus which they have 

 devised for determining molecular weights 

 by the boiling-point method . They both call 

 attention to the great influence of pressure 

 on the boiling point and the necessity of 

 making corrections for it. The two methods 

 vary in details, the apparatus of Orndorfif 

 and Cameron being much simpler and easily 

 made by any student, while speciallj' con- 

 structed apparatus is needed for Hite's 

 method. Numerous examples are given by 

 both of very satisfactorj' results obtained. 



Seldner has tried parallel experiments to 

 those of Gautier in which diacetamide is 

 formed by heating acetonitrile and acetic 

 acid together. He used glutaric acid and 

 its nitrile, and whether he mixed glutaric 

 acid and acetonitrile, or glutaric nitrile and 

 acetic acid, or glutaric acid and glutaric 

 nitrile, in each case he obtained the same 

 product, the glutaramide. DeChalmot, 

 who has been studying the pentoses of 

 plants, advanced the hypothesis that in 



