AGRICULTURAL BOTANY. 627 



Toxic and antagonistic effects of salts as related to ammonification by- 

 Bacillus subtilis. C. B. LiPMAN (Hot. ilnz.. '/N {1909), No. 2, i)i). 105-l,io, figs. 

 •p). — The effect of the chlorids of calcium, magnesium, potassium, and sodium, 

 as shown on the activity of B. subtilis, is reported upon. 



Each of the 4 chlorids was found toxic in the order enumerated, calcium 

 chlorid being the most toxic and sodium chlorid the least. This is said to be 

 quite diftVrent from the results with higlier plants where niaguesium is the 

 most toxic and calcium the least. There were found to l)e marked antagonisms 

 existing between calcium and potassium, magnesium and sodium, and potassium 

 and sodium. No antagonism was found to exist between magnesium and cal- 

 cium, but the toxic effect of each is inci-eased by the addition of the other. 



These experiments are held to have practical application because of the fact 

 tliat the salts experimented with are all found in soils in greater or lesser 

 amounts, and in some soils they ai-e present in excess. 



On similarity in the behavior of sodium and potassium, W. J. V. Oster- 

 HOUT (Jiot. (la:;., J,8 (1909), Xo. 2. pj). 9,S-I0.'f, fly.s. J). —The author carried on 

 two extensive series of experiments with the chlorids of sodium and potassium 

 to determine the commonly accepted statement that potassium and sodium, 

 while agreeing closely in chemical behavior, have fundamentally different effects 

 upon plants. Most of the experiments were carried on with wheat, but other 

 plants as algre, liverworts, Equisetum, and various genera of flowering plants 

 were also used. 



The results obtained show that the accepted idea that sodium and potassium 

 have entirely different effects ui)on plants is not valid in the field of toxic and 

 protective action, but that their behavior shows the close similarity which would 

 be expected when their near chemical relationship is considered. 



Some notes on the modifications of color in plants, H. Kkaemer (Science, 

 n. ser., 29 (1909), No. 151, p. 828). — In a paper presented before the American 

 Philosophical Society, in which the author first reviews the previous work on 

 the control of color in plants, an account is given of his experiments in using 

 various chemicals which were either sui)plied to the plants in the form of solu- 

 tions or added to the soil in solid form. 



When the white rose Kaiserin was supplied with potassiurn hydrate, potassium 

 carbonate, calciimi hydrate, and lead acetate, red pigments were developed in 

 the basal portion of the petals. This rose tends to a yellowish color but never 

 shows pink or red, and therefore the red color produced in the petals was a 

 new character. The explanation offered is that either the added chemical 

 reacted directly with the compound already present in the petals or induced 

 the formation of an entirely new substance in the petals, or that the color 

 substance was formed in other i)arts of the plant and transported to the petals 

 through the influence of the chemic;ils. 



The red-flowering form of Hi/draiificd otaksa gave blue flowers when growing 

 in either sand or garden soil and supi)lied with potassium and aluminum sul- 

 phate or aluminum suli)hate and calcium hydrate. In those plants grown in 

 sand and supplied with a nutrient solution and potassium carbonate l)lue 

 flowers were also produced. The flowers remained pink or red when grown in 

 either soil or ;;and and fed with a nutrient solution to which ii-on and ammonium 

 sulphate or lead acetate was added. The original color of the plants was con- 

 siderably intensified, due to the presence of lead acetate. In the case of plants 

 gi'owiT in soils sujtplied with potassium carbonate there was no change in color. 



The effect of salts upon pigments, E. A. Bunyard ((lard. Chrnn.. ,i. so:. .'/6 

 (1909), No. /ISO, 1)11. 97, 98). — After giving an account of the experiments of 

 Kraemer, described above, the author calls attention to the effect of cold on llie 

 changing of color in i)Iants. The rose Frau Karl l>ruschki had the outer peiiils 



