1 882.] Scientific News. 171 



juices had remained as sweet and clear as when they were prepared 

 in London. * * * * I took advantage of the clear weather 

 this year to investigate the action of solar light on the develop- 

 ment of life in these infusions, being prompted thereto by the in- 

 teresting observations brought before the Royal Society by Dr. 

 Downs and Mr. Blunt, in 1877. The sealed ends of the flasks 

 being broken off, they were infected in part by the water of an 

 adjacent brook, and in part by an infusion well charged with or- 

 ganisms. Hung up in rows upon a board, half of the flasks of 

 each row were securely shaded from the sun, the other half being 

 exposed to the light. In some cases, moreover, flasks were placed 

 in a darkened room within the house, while their companions 

 were exposed in the sunshine outside. The clear result of these 

 experiments, of which a considerable number is made, is that 

 by some constituent or constituents of the solar radiation an 

 influence is exercised inimical to the development of the lowest 

 infusoria. Twenty-four hours usually sufficed to cause the shaded 

 flasks to pass from clearness to turbidity, while thrice this time 

 left the exposed ones without sensible damage to their transpa- 

 rency. This result is not due to mere differences of tempera- 

 ture between the infusions. On many occasions the temperature 

 of the exposed flasks was far more favorable to the develop- 

 ment of life than that of the shaded ones. The energy which 

 in the cases here referred to prevented putrefaction was energy 

 in the radiant form. In no case have I found the flasks ster- 

 ilized by insolation, for, on removing the exposed ones from the 

 open air to a warm kitchen, they infallibly changed from clear- 

 ness to turbidity. Four-and-twenty hours were in most cases 

 sufficient to produce this change. Life is, therefore, prevented 

 from developing itself in the infusions as long as they are ex- 

 posed to the solar light, and the paralysis thus produced enables 

 them to pass through the night tunc without alteration. It is, 

 however, a suspension, not a destruction, of the germinal power, 

 for, as before stated, when placed in a warm room, life was in- 

 variably developed. * * * It would also be interesting to 

 examine how far insolation may be employed in the preserva- 

 tion of meat from putrefaction.— Professor Tyndall before British 

 Association, 188 1. 



SCIENTIFIC NEWS. 

 — The Annual Report of the Chief Signal Officer for i88r, 

 show that this Bureau was never in more efficient order, nor 

 doing more to promote scientific as well as purely practical 

 interests. For example Gen. Hazen reports that he has endeavored 

 to bring this service into active sympathy and cooperation with 

 the ablest scientific intellects of the country. "In this direction 

 and in response to my request, the Natural Academy of Sciences 

 ha s appointed an advisory committee of consulting specialists 



