March 14, 1913] 



SCIENCE 



423 



the species bearing generalized roots may have 

 a relatively wide distribution, occurring in 

 ■widely different habitats. Cowles" gives an 

 interesting example of the relation between 

 root variation and species range. The red 

 maple grows in swamps and also on dry 

 grounds. The root character of the tree on 

 the two habitats is very unlike. In the 

 swamps the tap root is not largely developed, 

 but the laterals are prominent, while in the 

 dry situation the reverse is the case, the tap 

 root being the leading characteristic of the 

 root-system. 



The problems which deal with the presence 

 of trees are primarily physiological and have 

 mainly to do with the absorption and con- 

 servation of water. Each of these capacities 

 varies with the species. Of the root relations 

 that of the root-water table is of prime impor- 

 tance, owing to the fact that the soil horizon, 

 tapped by the roots of trees, derives, by capil- 

 larity, from the level of ground water, its 

 perennial supply of moisture. In the semi- 

 arid regions probably the roots of most trees 

 attain to the perennially moist soil, sometimes 

 to the water table itself, at least for a portion 

 of the year, and, in the more humid regions, 

 the roots frequently do so. In both regions, 

 certainly in the former, wherever such is not 

 the case, a variety of factors, which need not 

 be discussed in this place, are of greater im- 

 portance in the survival of the species than 

 the water table depth, although the character 

 of the root-systems may still be of much, pos- 

 sibly of definitive, importance. 



W. A. Cannon 



Desert Laboratory 



INORGANIC COLLOIDS AND PROTOPLASM' 



Bredig" has shown that inorganic colloidal 

 solutions, such as silver, platinum and gold, 

 may act as catalyzers in certain chemical re- 



" ' ' Text-book of Botany, ' ' Vol. 2, Ecology, p. 

 506. 



'Presented in abstract form to the Columbia 

 University Biochemical Association and outlined in 

 the Biochemical Bulletin, II., 1, 1912. 



' " Anorganische Fermente, " Leipzig, 1901. 



actions, such as the reduction of hydrogen 

 peroxide to water, and while chemists have 

 studied the problem of the action of catalyzers 

 from this standpoint, biologists have signally 

 avoided attempts' to determine whether the 

 activities of the enzymes of the organism can 

 be imitated by these inorganic catalyzers. It 

 must be remembered in any such examination 

 that, as Ostwald* has demonstrated, along with 

 others, enzymes of any nature are incapable 

 of instigating a reaction, but their function is 

 solely that of modifying the Guldberg-Waage 

 mass action equation for a given instance, 

 either accelerating or retarding a reaction al- 

 ready in progress. Therefore, we should not 

 expect to find a striking modification of the 

 actions or of the structure of any organism, 

 if any effect were obtained by the application 

 of inorganic " enzymes." 



In a series of experiments, I attempted to 

 determine whether colloidal platinum and a 

 colloidal gntta percha'' gave evidence of any 

 effect upon simple organisms, such as proto- 

 zoa and single-celled plants. Platinum black 

 was obtained by the use of the house current, 

 reduced to about 70 volts, passing it through 

 a lamp-board, the current delivered to water 

 which had been glass-distilled, the electrodes 

 being of platinum, according to the Bredig 

 method.' In order to be certain that the so- 

 lution was desirable for experimentation, it 

 was examined over a Zeiss dark-ground con- 



'Benj. Moore (in "Eecent Advances in Physi- 

 ology and Biochemistry. ' ' L. Hill, Edt. London : 

 Edward Arnold, 1908; Chapter 4, p. 122) men- 

 tioned having performed injection experiments 

 with platinum sol on animals, but he gives no 

 details; he obtained negative results. Autolysis 

 has been shown to become accelerated under the 

 influence of colloidal metals. (See Ascoli and 

 Izar, Biochem. Zeitschr., Bde. 5, 7, 10, 14 and 17; 

 also Doerr, same journal, Bd. 7.) 



■"'Uber Katalyse, " Vortrag auf d. Ges. d. 

 Naturf. u. Arzte, 1901. 



° Professor Henry A. Perkins, of the Jarvis 

 Physical Laboratories, Trinity College, prepared 

 this solution after the formula which he used in 

 the laboratory of Professor Perrin at the Sor- 

 bonne, and I am indebted to him for the kindness. 



'Zeitschr. f. angew. Chemie, 1898, p. 951. 



