OAK-LEAF POISONING OF DOMESTIC ANIMALS. 3 
Letions. — They are those of gastroenteritis and of nephrocystitis. The first are 
generally closely related to the intensity and progress of the disease. The second are 
more accentuated. The kidneys are doubled or tripled in volume, show ecchymotic 
spots on their surface, hemorrhagic foci in their parenchyma, inflammation of the 
pelvis and the destruction of the uriniferous tubules or their obstruction by fibrinous 
coagulum. The bladder is almost always turned back upon itself and is nearly empty 
or contains a small quantity of dark urine; the mucous membrane is inflamed. 
The study of the urine, which is the more interesting part in the history of hematuria, 
has been much neglected up to the last years. Only the most evident physical 
characters have been noted, and there has been established only one essential point, 
the presence of or absence of blood corpuscles in the urine. Stockneth denies their 
existence in this liquid, while most French authors admit it. M. A. Robin has made a 
thorough study of the urology, and we can not do better than to quote a resume of his 
observations. 
"The urine is viscous, with alkaline reaction, with an ox-house odor, rich in sedi- 
ment formed largely of coagulated albuminoid matter and tinted brown. The blood 
corpuscles are rare, but one finds crystals of urate of ammonia, a very little carbonate 
of calcium, some drops of oil, some leucocytes, no oxalate of calcium, a little urea in a 
normal condition, a considerable diminution of the hippurates and a notable increase 
of the chlorids, a little phosphoric acid, albumen in considerable quantity and also 
some urohematin and hemoglobin. No trace of sugar." 
From his analysis, M. Robin concludes that during the course of the disease "the 
organism loses heavily in urea and especially in the chlorids, losses which become 
more evident as the animals eat less, that the uric acid replaces the hippuric, the 
urine of the sick animals approaching temporarily the condition of that in carnivores; 
that the salts of calcium diminish in the liquid and disappear in the sediment; that 
the free oil and the casts increase and appear in connection with the defervescence; 
lastly that the affection appears to be a hemoglobinuria rather than a true hematuria." 
What is the substance producing this hemoglobinuria? It must be found in the 
young shoots and new leaves of the oak, but it is to be noticed that those. of the horn- 
beam, ash, alder, hazel, privet, cornel, spruce, pitch fir, gorze, and broom under the 
same conditions are capable of producing similar results. All these shoots and leaves 
are rich in tannin, and investigators have been led to consider this body as the one 
producing the harm. We will discuss this opinion. 
To sustain it, it can be argued that the tannin is in much larger proportion in the 
accused plants, and especially in the oak in the spring than in the winter, and that 
it is more abundant in the young oaks than in the old since in the latter the tannin is 
transformed to gallic acid and then little by little into brown extractives. 
It is learned that the content of tannin in the plants containing tannin has relation 
to the physiological activity of the tissues in such a way that its maximum is found 
in the young organs, like the sprouts, young branches, and the first leaves, the form- 
ing tissues, the cambium and the phellogen. 
Does it follow that it is a greater introduction of tannin into the economy which 
occasions the "mal de brou?" I do not think so. As a matter of fact animals are 
given food which is just as rich in tannin and which, nevertheless, occasions no acci- 
dents in spite of the continuance of such treatment. We may mention the acorns 
which in the wooded districts, in France and elsewhere, are given to all animals, 
horses, fattening animals, and swine, without ever bringing on hematuria, but with 
excellent results. The leaves of the vine are, among foliaceous organs, especially 
rich in tannin — from time immemorial these have been collected and preserved in 
silos as food for animals in winter. Who has ever known the "mal de brou " to follow 
their consumption? In the Scandinavian country, in the north of Russia and of 
Asia, especially among the Baskir tribes, they use the bark of the birch, pine, spruce, 
