Memoirs of the New York Botanical Garden Volume 4

Memoirs of the New York Botanical Garden Volume 4

List price: US$19.99

Currently unavailable

Add to wishlist

AbeBooks may have this title (opens in new window).

Try AbeBooks

Description

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 edition. Excerpt: ...seeds was doubtless here (as in other experiments) a source of error, by emphasizing individual variations, but this could not well be eliminated on account of the scarcity of the radium, and the comparatively short period of time that any given preparation was at my disposal. Fig. 16. Effect on the Growth of Zea Mays of Various Durations of Exposure of the Grains, before Planting, to Radium Rays. Activity, 1,500,000. Interpretation of the results is greatly facilitated by inspection of the curves (figures 10-12). In Figure 10 it is clearly shown that, for an exposure of 16 hrs., the effect of the rays from the preparations of 1,500,000 x and 1,800,000 x varied directly as the activity of the radium. The same fact is clearly indicated in Figures Ii and 12, where the exposures were respectively for 24 and 33 hours. The immediate effect of exposure for 16 hrs. to the radium of 10,000 x (figure 10) was a greater retardation of growth than that produced by the next more active preparation, but from the third day the plants of this culture grew faster, so that, from this time on, the rate of growth varied inversely as the strength of the radium. In Figure I1, also, growth following exposure to the larger amount of the weaker radium is shown to be less at first than after exposure to the radium of 1,800,000 x, but soon becomes greater, though the indicated effect of the radium of 1,500,000 x is less than that of either the 10,000 x or the 1,800,000 x radium. 120 110 100 90 80 70 g 60 J 50 40 SO so 10 0 10 11 15 12 IS Day of month Fig. 17. Effect on the Growth of Zea Mays of Various Durations of Exposure of the Grains, before Planting, to Radium Rays. Activity, 1,800,000. If we consider the effect of rays of the same strength allowed to act for...show more

Product details

  • Paperback | 82 pages
  • 189 x 246 x 4mm | 163g
  • Rarebooksclub.com
  • Miami Fl, United States
  • English
  • black & white illustrations
  • 1236617681
  • 9781236617682