92 BOTH SIDES OF THE BLUE GLASS QUESTION. 



Pleasonton's grapery it appears that only every eighth row of panes was 

 blue. Some of the results alleged to have been obtained by exposing ani- 

 mals and plants are as follows: Twenty grape vines, in their .second year, 

 after being set out under the blue glass, bore 1,200 pounds of splendid fruit. 

 A very weak Alderney bull calf was in four months developed into a strong 

 and vigorous bull. Heifers when kept under blue glass may safely bear 

 3^oung when eighteen months old. A weak child, weighing but three and 

 ii half pounds at birth, weighed at the end of four months twenty-two 

 pounds — the light in this instance having come through blue curtains. 

 Two major generals with rheumatism were cured in three days. A young 

 lady whose hair had come out regained her tresses; and to these must be 

 ndded various other cures of severe ailments which we have not space here 

 to recapitulate. The above are the alleged facts; and we propose to con- 

 sider the supposed discovery in the light of previous investigations. 



"With reference to the theories of eleclricity, etc., advanced by Gen. 

 Pieasonton to account for his phenomena, their absurdity is so complete 

 that we shall waste no time over them. The important question in the mat- 

 ter, and the only one in which the public is interested, is whether or not 

 blue glass is capable of producing all or any of the results imputed to its 

 use. In order to clear the way for the examination of the investigations, 

 the records of which we have carefully collected, let us consider first those 

 which G-en. Pieasonton quotes in support of his views. These are (1) Seune- 

 bier's researches, which go to show that the blue and violet rays are the 

 most active in determining the decomposition of carbonic acid in plants, 

 and (2) experiments of Dr. Morichini, repeated by Carpa and Eidolfi, prov- 

 ing that violet rays magnetized a small needle. The first statement has 

 been totally disproved. Dr. Yon Bezold, in his recent work on color, states 

 the 'chemical processes in plants, as far as they are dependent upon light, 

 are princip)ally caused by the rays of medium and of lower refrangibility. 

 The development of the green color of the chlorophyll, the decomposition 

 of carbonic acid, as well as the formation of starch, etc., in the grains of the 

 chlorophyll, are induced by the red, green, and orange rays.' The blue, 

 violet, and ultra violet rays, the same authority goes on to explain, influence 

 'the rajjidity of growth, compel the so-called zoospores to move in certain 

 directions, and alter the positions of leaves,' etc. In confirmation of this, 

 we have Sach's experiments in 1872, which show that light, transmitted 

 through the yellow solution of potassium chromate, enables green leaves to 

 decompose over eighty-eight per cent, of carbonic acid; while that passed 

 through blue ammonia copj)er oxide decomposes less than eight per cent. 

 This proves the superiority of the yellow ray to decompose carbonic acid; 

 -and this fact Prof. J. W. Draper discovered a long time ago by the direct 

 use of the spectrum. In still further confirmation, we nisiy cite the investi- 

 gations of Yogel, Pfeiffer, Selim, and Placentim. The last three have con- 

 ducted researches in full knowledge of those of Gen. Pieasonton, and their 

 experiments show that yellow rays are more promotive of the evolution of 



