Note 173 — CHAP. XII. INSTRUCTIONS FOR COLLECTING AND PRESERVING INSECTS—A COPIOUS LIST OF MICROSCOPIC OBJECTS. BY THE EDITOR.

To ascertain the true configurations of salts, particular attention should be paid to obtain them genuine; it may therefore be proper to apprize the reader, that some of those above enumerated are not easily procured in that state; consequently, though they exhibit pleasing figures, yet they may not be those of the real salt purposed to be investigated. Many hundred weights of some salts are annually manufactured, and sold under names very different from what they really are. Nor is this circumstance confined to salts only: for want of botanical knowledge, preparations of different plants have been frequently sold possessed of medical properties very different from those intended. A valuable medicine, the extract of Hemlock, for instance, instead of being prepared of the conium maculatum, has been made in large quantities of the chærophyllum sylvestre, and thus administered! On this unpleasant subject I could enlarge, were it not digressing from that before us. Whilst such evils exist, need we wonder if the physician as well as the patient are often disappointed in the beneficial effects expected from the adhibition of medicines?