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252 indicate a quantity of copper less than 0.5 milligramme. Mr. Merrick's method consists simply in concentrating to a very small bulk the solution suspected to contain copper, and then depositing the copper, if present, upon platinum, by the battery. He uses for a depositing-cell a very small test-tube, on a foot cut off, so as to give a vessel about one and a half inch deep. Into this is introduced the solution acidified with sulphuric acid, and a platinum anode and cathode—each about an inch long and one-eighth inch or less wide—are hung face to face, and very close together; and, the circuit being completed, very satisfactory deposits of copper are obtained with incredibly minute quantities of the metal. The amounts are determined by the increased weight of the cathode (which is provided with a platinum wire soldered on with gold, by which it can be hooked to a balance) and on the loss of weight of the same after washing with nitric acid. The platinum is polished and heated red-hot before the first weighing, and then gently heated before hanging in the solution. The contrast in color between deposited copper and bright platinum is, of course, striking and characteristic. In this way, 0.1 milligramme of copper may be, the author thinks, safely determined; while for mere qualitative analysis this method may be employed where the amount is even smaller.

Award of the Bigsby Medal to Prof. O. C. Marsh.—Prof. P. Martin Duncan, President of the Geological Society of London, in announcing the award of the Bigsby Medal to Prof. O. C. Marsh for his services in investigating the paleontology of the Vertebrata, paid a high but well-merited compliment to the learned Yale professor. Said Prof. Duncan: "He has distinguished himself by studying the fossil remains of nearly every great group of the vertebrata from the palæozoic, cretaceous, and cainozoic strata of the New World. The field of his research has been immense, but it has been very correct; and his descriptive and classificatory paleontological work indicates his effective grasp of anatomical details, and his great power as a comparative osteologist." Prof. Duncan then enumerated in some details the chief lines of research pursued by Prof. Marsh, and was followed by Mr. Hulke, himself a paleontologist, who heartily approved all that had been said by the president with respect to the value of Prof. Marsh's services to paleontology. "These," he said, "are so numerous and important as to mark an epoch in this line of research. The present recognition of the value of his labors will doubtless prove an incentive to fresh work."

What is Moderate Drinking?—The advocates of total abstinence from intoxicating liquors are wont to condemn even a moderate use of stimulating drinks, on the ground that "moderate drinking is the parent of excessive drinking." The Lancet questions the correctness of this proposition, but in its negative definition of what is meant by "moderate" drinking the votaries of Bacchus will find very little comfort. "The man," says the Lancet," who begins the day with a 'soda-and-brandy,' has very little respect for his constitution, and if he does not alter his habits, they will alter his health. Odd glasses of beer and glasses of spirit in a forenoon do not come within the range of moderate drinking. That is not moderate drinking which adds fifteen or twenty beats to the pulse, or which flushes the face. Finally, all casual drinking is bad, presumably, and not moderate drinking. The system will not receive food merely as a matter of conviviality, at all sorts of odd hours. Still less will it receive with impunity drink in this way. Drinking which disturbs sleep, either by making it heavy or by driving it away, is not moderate. Moderate drinking is that which consists with a clean tongue, a good appetite, a slow pulse, a cool skin, a clear head, a steady hand, good walking-power, and light, refreshing sleep. It is associated with meals, and is entirely subordinated to more convenient and less objectionable forms of food. That such drinking produces drunkenness, has yet to be proved, as it has yet to be proved to be essential to health."

Retention of Impressions by the Retina.—Does the retina retain in death the image last impressed upon it? That such is the case has been asserted, but hitherto the evidence has not been satisfactory, to say