THE POPULAR SCIENCE MONTHLY.
Concerning the possibility of communicating so powerful an odor to a vast quantity of water by means of an almost infinitesimal amount of algæ, the author says: "That this odorous material was extremely volatile, was obvious. It soon vanished from water left at repose in the open air. Heat expelled it still more rapidly. It was for this reason that no trace of it could be perceived in the open reservoirs where it could escape as rapidly as it was generated, while in the closed conduit from the West Rush Reservoir to the Mount Hope Reservoir, and in the street mains of the city, it was prevented from escaping except when a faucet was opened. Again, in its extreme volatility we have the clearest explanation of the fact that so minute a quantity of odorous material could infect so large a quantity of water. A single flower will instantly communicate its perfume to every particle of the air in a large room. A grain of musk, or a shred of scorched animal tissue, will taint a vast volume of air with no loss of substance appreciable to the most delicate balance."
Regarding the public health, there is no evidence furnished that warrants even a suspicion of any deleterious effect, and this is strictly in accordance with what would be expected if the above explanation is correct.
To the question, "Can any measures be taken to prevent a recurrence of this trouble?" the following answer is made: "It is useless to attempt a reply until we come to understand the causes and conditions precedent to such results. This knowledge can evidently be acquired only by long and patient observation, if obtained at all; and, if obtained at last, it might be only like our knowledge of the laws of meteorology, which indeed enables us to predict the coming changes of the weather with great certainty, but which confers on us no power whatever to control it. On the other hand, it is at least conceivable that, if we understood the life-history of these offensive algæ, and the conditions favorable or unfavorable to their growth and multiplication, we might possibly be able to prevent or favor their growth, or to hasten or retard their destruction in such manner as to prevent the recurrence of the trouble."
|A RUN THROUGH THE MUSEUMS OF EUROPE.|
By THOMAS M. BREWER.
IN 1875-'76 the writer, having a general interest in the science of ornithology, and making a special study of that somewhat neglected branch which relates to the peculiarities of birds' nests and eggs, devoted, at intervals, more than a year to visiting some of the principal museums of the Continent of Europe, and afterward of