Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.

free acid in the urine without the uric acid being set free, though this often requires many hours to crystallize out. If, then, you wish to know if the urine is too acid, you must leave the vial at rest for twenty-four, and sometimes ninety-six hours, and if there be too much acid, red crystals of uric acid ivill be very distinctly seen adhering to its sides, or deposited. The microscope may tell you quicker, but it will not tell you more surely, than the naked eye. Whatever the degree of reddening of the litmus, or the amount of urate-of-ammonia sediment, you cannot with truth speak positively of excess of acid being pres- ent, unless you see uric acid crystals ; and it is only when free acid is present in the urine that alkaline remedies are absolutely necessary." In taking a sample of urine for test, I would here add, it had better be of that made early in the morning, and it should be passed altogether as usual in the ordinary cabinet (chamber) vessel, and then stirred, so as to mix the whole, just before pouring it into the clean vial; and this should be done imme- diately after its passage by the patient. Perhaps it would not be amiss to add, in this connection, a condensed philosophic view of the phenomena of inflammation, as given by Dr. R. Billings, much in these words: " The con- traction of the heart is muscular; that of the arteries is elastic. The heart contracts and relaxes alternately; the arteries, on the contrary, keep up, by their contractile tissue, a constant con- tractile or elastic pressure on their contents; not, as has been commonly supposed, an alternate contraction and relaxation, but a continued contractile effort, both longitudinally and trans- versely, which is overcome by the action of the heart. When there is much blood sent into them, they are distended ; and if there be little blood sent into them, as after hemorrhage, their tendency to contract causes them to close, so as to keep always full, and to preserve a continuous stream of blood, even during the temporary relaxation of the heart; and the arteries yielding and adapting themselves to the pressure of the heart, and re- contracting on their contents, whilst the heart is relaxed and filling, is the cause of the equability of the stream in the veins.