powerful glasses. The after part of the day, and usually no small portion of the night, were spent in registering his observations and writing out a detailed account of them, as well as in finishing his drawings. Such was his enthusiasm that he often used to wish that he had but one year of perpetual light and heat, to enable him to work without interruption. The whole of this laborious task, too, was executed while in a state of great bodily infirmity, and amid mental distractions arising from a cause to which we shall have immediate occasion to advert. Of the treatise resulting from these exertions, Boerhaave affirms, that all the ages from the commencement of natural history to his time, have produced nothing equal—nothing to compare with it. It is, certainly deserving of the highest commendation for indefatigable research, minute and accurate description, and elaborate delineations of internal organs. Indeed it may be said to have laid the foundation of an accurate and philosophical history of the Bee, and at the same time to have contributed largely to advance our knowledge of the structure of insects in general. When we consider how many interesting particulars Swammerdam brought to light, it will not appear surprising that several singular facts escaped his observation. The comparatively ample knowledge we now possess of the subject is due to the accumulated labours of many different individuals, and it might have been much more limited than it is had it not been for the happy expedient of employing glass hives, a thing which had not been thought of in Swam-
