P OP ULAR MIS CELL ANY. 



425 



of trees of the same species, the same size, 

 and presumably the same age, standing 

 within twenty feet of each other, on the 

 same kind of soil, cut down the same year, 

 and, so far as he could judge, subject to the 

 same conditions throughout, " one showing 

 a large ring where its neighbor would show 

 only an average one, and in some I'ew cases 

 they showed the opposite." While he can 

 not account for the spasmodic production 

 of single rings of large or small growth, 

 interspersed here and there among those of 

 average size, he has been able to trace suc- 

 cessions of large or small rings to some 

 plausible cause. In making some surveys, 

 he had had occasion to refer to two trees 

 which had been marked in the Government 

 surveys of fifty years before, as "witness- 

 trees," to aid in identifying corners. Both 

 were described in the field-notes of those sur- 

 veys as ash-trees three inches in diameter. 

 One had grown to be eighteen inches in 

 diameter ; while the other had added only a 

 half inch to that dimension, but the re- 

 quired rings of growth could be plainly seen 

 under the glass. The former tree had had 

 a good soil on level ground, while "all of its 

 adult rivals had been blown down by a 

 tornado which had passed over the spot. 

 The latter tree " stood in dissolved sand- 

 stone for soil, on the top of a narrow ridge, 

 between three large oaks, which robbed it 

 of sunlight and rain, and nearly all the soil 

 nourishment. It had but five or six small 

 branches for a top, and but few leaves to a 

 branch; under such conditions it did well 

 even to exist." Mr. Campbell read the 

 history of two oaks as it was revealed to 

 him by the rings and the configuration of 

 the ground. One sprouted from the seed 

 in 1502 ; the other, twenty feet distant from 

 it, in 1594, or ninety-two years afterward. 

 "In nsi a tornado from the northwest 

 blew down a still older oak, which in its 

 fall struck against and greatly damaged 

 the top of the one bom in 1502." The 

 two younger trees had been freshly cut 

 down when the author examined them. 

 " Their stumps were about four feet across, 

 and there was not over an inch difference 

 between their diameters, though ninety-two 

 years difference in their ages. The younger 

 had a large, healthy top, no broken or dead 

 limbs, and it had put on rings of growth 



from the beginning of more than average 

 size. The older one had been injured in 

 its branches by the fall of the still older 

 tree before mentioned (in 1701), and for 

 fifty-seven years had put on very small 

 rings of growth, . . . when a new set of 

 branches developed to take the place of the 

 damaged ones, and the rings began to in- 

 crease in size and gradually attained to the 

 average. I examined their tops, which co- 

 incided with what has gone before. There 

 were the peculiar knots in the top of the 

 older one where dead limbs had rotted off 

 and were healed over. During this delay 

 the younger oak caught up with the older 

 one in size. The size of a tree is a very 

 uncertain indication of its age." Mr. Camp- 

 bell examined one tree that was six hundred 

 years old, and learned from it that " at the 

 age of about two hundred years it had 

 some ill fortune which caused it to form 

 about one hundred small rings. It then re- 

 gained its health and formed normal rings 

 for about one hundred and forty years, when 

 another mishap caused small rings till with- 

 in the last fifty years, when it was putting 

 on fair growths again." 



Uses and Natnre of Physiological Ex- 

 pcrinient.— Dr. H. Xewell-Martin has replied 

 to an accusation made against him in the 

 London " Zoophilist," of practicing cruelty 

 in his physiological experiments on living 

 animals. First, he responds to the charge 

 that the experiments are useless, saying : 

 " Every one is aware that in very many 

 cases severe fevers result in death. It is 

 well known to most medical men that most 

 such deaths are due to failure of the heart. 

 This failure is caused by too rapid beat, the 

 organ not getting rest enough between its 

 strokes for nourishment and repair. This 

 quicker beat might be due to any of four or 

 five possible causes. ... To ascertain which 

 of them was mainly responsible for it, and 

 thus throw light upon the proper means to 

 be adopted to save life, was the object of 

 my research ; an object which, I am proud 

 to say, I in large measure attained." In re- 

 gard to the amount of pain inflicted in the 

 experiments, his first endeavor was " to put 

 out of action, to kill, all parts of the body 

 but the heart and lungs. These do not pos- 

 sess consciousness, and are incapable of suf- 



