The Planet Mars 205 



eight days. It was now proposed to use gas furnaces, by 

 which a uniform temperature could be maintained for 

 weeks together. 



Dec. 2Oth, 275th meeting. Sir W. Grove compared 

 observations of the planet Mars, which he had made last 

 September under very favourable circumstances, with others 

 made in 1862, when the planet was also unusually near the 

 earth. They showed considerable differences. In 1862 

 the dark markings were in the south hemisphere of the 

 planet, and had jagged or festooned edges. This year 

 a dark patch, shaped like an open hand with fingers and 

 thumb pressed together, lay across the equatorial regions. 

 The changes might be due to clouds in drift, but more 

 probably these produced an effect on permanent markings. 

 His telescope was 4-6 inches aperture, made by Cooke, of 

 York. He said, in reply to a question by Mr. Ball, that the 

 markings were substantially the same, though not identical, 

 for the short periods during which he had observed them 

 this year. Mr. Huggins, though he had not been able 

 personally to observe the planet, because his own telescope 

 was employed on spectroscopic investigation, had inspected 

 some admirable photographs taken at Madeira by Mr. Green. 

 Here the changes since 1862 were not so great as Sir W. 

 Grove supposed, since the old markings, though modified, 

 retained their essential character. 



1878. Jan. 3ist, 276th meeting. Dr. Burdon-Sanderson 

 said that he and Mr. Ewart, of University College, had been 

 investigating Dr. Koch's discoveries of the bacillus which 

 caused splenic fever, an extremely contagious and fatal 

 disease of cattle. The organism, so rapidly developed in 

 the blood and tissues, and particularly the spleen of the 

 affected animal, can also be cultivated, retaining its viru- 

 lence, in other soil. It can be communicated to a healthy 

 animal either by the insertion of a bit of the plant or by 

 inoculating it with the blood from a diseased one. Mr. Ewart 

 had been able to study the development of the protophyte 

 from the spore onwards more completely than had hitherto 

 been done, and had found it to afford characters even more 



