Dept.] 
NATURAL SCIENCES OF PHILADELPHIA. 
5 
that the temperature of the blood underwent a marked decrease with each de- 
pletion. Being, at the first, 100° Fahr., it fell by degrees to 96.2°. During 
subsequent convalescence it again gradually rose, being at the time of the last 
examination, 98.7'^. 
Intestinal absorption. — Dr. Joseph Leidy made the following remarks : 
The observation of Goodsir, that the epithelium of the intestine appears 
frequently to be thrown off in laminae, exposing the basement membrane so as 
to absorb directly, has been generally denied by others ; but the true mode of 
shedding the columnar epithelium of the intestine has not yet been demon- 
strated. In examining the intestinal canal of insects, as flies, beetles, grass- 
hoppers, &c., the structure of which, although very delicate, is essentially the 
same as that of the intestine of higher animals, having a columnar epithelium 
upon a basement membrane, and beneath this a muscular tunic — on placing 
the mucous membrane upon the object-glass of a microscope while yet living, 
Dr. Leidy observed that, when a little water was added, endosmose taking 
place, the oldest and thinnest cells received the fluid most rapidly, while these 
were pushed out by the presence of others, thus squeezing the liquid through 
them. It is, therefore, probable that the epithelium is shed cell by cell, the 
oldest cells being crowded out by the new ones forming beneath. This can be 
seen by any one under the microscope in the intestine of the common house- 
fly. The nutritious matter in contact with the epithelial cells passes into them 
by endosmose, and thence through the basement membrane into the subjacent 
vessels. Dr. Leidy has never seen the epithelium stripped off in layers, 
although he has often watched the process in mice, serpents, salamanders, and 
frogs, in all of which the mucous membrane has a similar structure. He has, 
however, very often observed the new cells pushing themselves between the 
old ones, altering their shape, — the round ones being seen at the bottom, and 
the elongated oval or pear-shaped ones above. 
Feb. 1st. Oxaluria. — Dr. J. Cheston Morris remarked that it is only within 
the last 35 years that the occasional occurrence of oxalate of lime in the urine 
has been noticed. At first it was only surmised to exist in this excretion from 
the fact that calculi were often found to consist partly of it. But soon after 
the perfection of the microscope, and its general employment in clinical investi- 
gation, octohedral crystals of various sizes and great brilliancy were observed, 
which were proved by chemical investigation to consist wholly of this salt. 
The discovery of the nature of these crystals would probably have been made 
earlier, had not observers been led astray by the fact that oxalate of lime, when 
precipitated ordinarily from solutions of lime-salts by oxalate of ammonia, is 
amorphous. Lehmann, however, states that when extremely dilute solutions 
are used, and the precipitate is examined with high powers, minute bctohedra 
may be distinguished. It is obvious, however, that in physiological chemistry 
some circumstance must exist, modifying the mode of formation of this most 
insoluble salt, as we find it occurring in quite large and beautiful crystals, as 
in the cells of various plants, and even in the urine of man and other mam- 
malia. This modifying circumstance I take to be the extremely gradual for- 
mation of oxalic acid in the course of the chemical changes constantly taking 
place in all organic fluids. The formation of oxalic acid is always due to the 
partial oxidation of the substance when it is procured, whether in the pro- 
cesses of nature, in the vegetable and animal kingdoms, or in our labora- 
tories by the action of nitric acid on sugar. Probably no other substance has 
undergone so rapid a change of opinion as to its pathological importance. Re- 
garded at first as a sure fore-runner of mulberry calculus, it was supposed to 
depend upon a peculiar diathesis as its cause. Then it was supposed to be due 
to the consumption of vegetables containing oxalates ; a view refuted by the 
utter insolubility of oxalate of lime in any of the fluids of the body, and the 
consequent impossibility of its penetrating the blood-vessels — yet supported by 
Wilson and Donne. It has been found to be increased by the use of carbonated 
liquors and of nitrogenous food ; after epileptic convulsions, in chorea, chronic 
1858.] 
