SCIENCE. 



81 



which it flows, while at the same time a record is made of 

 the volume of the fluid thus displaced. 



The more important work going on in the laboratory at 

 the time of my visit consisted of experiments in regard to 

 respiration, with special reference to the functions of the 

 glottis and epiglottis, and trials of disinfectants with a 

 view to ascertaining the temperature necessary to kill 

 germs. A series of experiments was also in progress for 

 testing the porosity of various stones used in building. 



The results of the original work performed here have 

 been recently published, together with an account of the 

 physical apparatus in use at the school. Accounts of the 

 most important investigations carried on during the last 

 year are contained in the following papers : " Growth as a 

 Function of Cells: Preliminary Notice of Certain Laws 

 of Histological Differentiation," by C. G. Minot ; " Effects 

 of the Respiratory Movements on the Pulmonary Circula- 

 tion," by H. P. Bowditch, M. D., and G. M. Garland, M. 

 D.; "Pharyngeal Respiration," by G. M. Garland, M. D.; 

 •' Functions of the Epiglottis in Deglutition and Phona- 

 tion," by G. L. Walton. This paper shows that the re- 

 moval of the epiglottis does not seriously affect deglut - 

 tion, and therefore it is not necessary for that process. 

 The epiglottis, however, plays an important part in form- 

 ing and modifying the voice, taking different positions 

 during vocalization, changes of pitch, quality, and in- 

 tensity. 



In the chemical laboratory I found that Professor Wood 

 had been examining the water-supply of Cambridge ; and 

 was then engaged in the investigation of the extent to 

 which arsenic is being used in the manufacture or orna- 

 mentation of articles in general use, such as wall-paper, 

 confectionery, playthings, etc. The results of this work 

 will be published in the next report of the State Board of 

 Health. Professor Wood is also writing the addition to 

 "Ziemssen's Cyclopaedia " on the subject of toxicology. 



Dr. William B. Hills was engaged upon a special inves- 

 tigation in regard to the localization of arsenic in the 

 animal economy. 



The most important feature of original work at the 

 school of late years has been Dr. Bigelow's introduction of 

 the new operation of litholapaxy. 



A number of interesting papers have been recently 

 written by members of the faculty, some of which contain 

 new discoveries of considerable scientific importance. I 

 cite two: "Effects of Certain Drugs in increasing or 

 diminishing Red Blood-Corpuscles," by Dr Cutter ; and 

 " Alterations in Spinal Cord in Hydrophobia," by Dr. 

 Fitz. 



The School of Agriculture and Horticulture, called " The 

 Bussey Institution," is located on the sunny slopes of 

 Forest Hills, about five miles southwest from Boston. The 

 labors of the professors connected with this institution have 

 been even more in the line of original research than of in- 

 struction, though of late the lack of a sufficient endow- 

 ment has interfered with the quality of work and the 

 publication of the results. 



A number of exceedingly interesting and valuable 

 papers, however, have appeared in the " Bussey Bulletin," 

 the titles of which give some indication of the character of 

 the work. I give a few of the more important : " Hybridiza- 

 of Lilies," by Professor Parkman ; ■' Diseases caused by 

 Fungi " — Professor Farlow ; Examinations of Fodders," 

 " Trials of Fertilizers," " Prominence of Carbonate of Lime 

 in Soil-Water," ■' Importance as Plant-Food of the Nitrogen 

 in Vegetable Mold" — Professor F. H. Storer ; "The 

 Potato- Rot," and " The Black Knot " (of plum and cherry- 

 trees) — Professor Farlow. — Popular Science Monthly. 



ON THE EFFECTS PRODUCED BY MIXING 

 WHITE WITH COLORED LIGHT. 



It was noticed several years ago that when white light 

 was mixed by the method of rotating discs with light of an 

 ultramarine (artificial) hue, the result was not what one 

 would naturally have expected, viz. : instead of obtaining 

 a lighter or paler tint of violet-blue the color inclined de- 



cidedly toward violet, passing, when much white was 

 added, into a pale violet hue. Two attempts have been 

 made to account for this curious fact : Briicke supposes 

 that the light which we call white is really to a considera- 

 ble extent red, and that the mixture of this reddish white 

 light with the blue causes it to change to violet. Aubert, 

 on the other hand, following a suggestion of Helmholtz, 

 reaches the conclusion that violet is really only a lighter 

 shade of ultramarine-blue. He starts with the assumption 

 that we obtain our idea of blue mixed with white from the 

 sky, which, according to him, is of a greenish-blue color. 

 We then apply, as he thinks, this idea to the case of a blue 

 which is not greenish, namely, to ultramarine-blue, and are 

 surprised to find that the result is different. 



It will be shown in the present paper that these expla- 

 nations are hardly correct, since they fail to account for the 

 changes, which, according to my experiments, are produced 

 in other colors by an admixture of white. I prepared a set 

 of brilliantly colored circular discs which represented all 

 the principal colors of the spectrum and also purple ; these 

 discs were then successively combined in various propor- 

 tions with a white disc and the effects of rapid rotation 

 noted, a smaller duplicate colored disc uncombined with 

 white being used for comparison. Under these circum- 

 stances it was found that the addition of white produced 

 the changes indicated in the following table : 



Vermilion became somewhat purplish. 

 Orange became more red. 

 Yellow became more orange. 

 Greenish yellow was unchanged. 

 Yellowish green became more green. 

 Green became more blue-green. 

 Cyan-blue became less greenish, more bluish. 

 Cobalt-blue became more of a violet blue. 

 Ultramarine (aitificial) became more violet. 

 Purple became less red, more violet. 



Exactly these same effects can be produced by mixing 

 violet with the above mentioned colors. These experi- 

 ments serve to explain the singular circumstance that when 

 complementary colors are produced by the aid of polarized 

 light, it is difficult or impossible to obtain a red which is 

 entirely free from a purplish hue, a quantity of white light 

 being always necessarily mingled with the colored light. 

 In the case of the red, orange, yellow, ultramarine, and 

 purple discs, I succeeded in measuring the amount of 

 violet light which different proportions of the white disc 

 virtually added to the mixture, and found that it is not di- 

 rectly proportional to the amount of white light added, but 

 increased in a slower ratio, which at present has not been 

 accurately determined. 



For the explanation of the above mentioned phenomena, 

 Brticke's suggestion that white light contains a certain 

 amount of un-neutralized red light is evidently inapplicable, 

 since the effects are such as would be produced by adding 

 a quantity not of red but of violet light, and for the present 

 I am not disposed to assume that white light contains an 

 excess of violet light. The explanation offered by Aubert 

 does not undertake to account for the changes produced in 

 colors other than ultramarine, and even in this case seems 

 to me arbitrary ; neither have I succeeded in framing any 

 explanation in accordance with the theory of Young and 

 Helmholtz which seems plausible. — Prof. O. N. Rood, 

 Ameiican Journal of Science 



BERNARD1NITE: ITS NATURE AND ORIGIN. 



By J. M. Stillman. 



In a previous number of this Journal 1 I published the re- 

 sults of a chemical investigation of a resinous substance from 

 San Bernardino, sent to me by Hon. B. B. Redding, which 

 was said to occur in the form of vein in detached masses, 

 and the vein to be traceable for three miles. The finders 

 (farmers or " ranchers " of that vicinity) sent at the same 

 time pieces of rock as vein-stuff which contained this pecu- 

 liar resinous substance in the crevices. Some months later 



'III, vol. xviii, p. 57. 



