Preparations of the nerves and blood vessels of the entire subject, distinct from the body, are made in a similar manner; fine specimens of which are contained in the Museum of Comparative Anatomy in the Garden of Plants. The endless variety and perfection of the preparations, models, &c., as a means of prosecuting anatomical studies at the present time, are strongly contrasted with those at the command of the student in the days of Harvey; when the vessels and nerves were imperfectly displayed with great labour and expense by the tedious process of dissecting them from the body and drying them on a board. Valuable specimens of these kinds of preparations from the cabinet of Harvey, are still scrupulously preserved in the cabinet of the Royal College of Physicians of London. It will only be necessary to add here, a few formulæ for the various kinds of injections used in the preparations of the blood vessels by the American and English anatomists, which will be observed to differ considerably from those used on the Continent, by reference to chapter seventh of this volume, where will also be found formulæ for the composition of varnishes: as regards the various methods of manipulation requisite for the preparation of each particular part of the body, these will be best obtained by the student’s personal application to the anatomical instructor or assistant connected with medical schools and teachers of practical anatomy. We have found, by experience, that the great secret of success in anatomical injections, consists in first heating the part, or subject, thoroughly in hot water, the temperature of which, for an entire subject must be continued for ten or twelve hours, or until the deepest parts are equally heated; secondly, to take the precaution to reduce the colouring matters to an impalpable powder, and use the injection at as high a temperature as possible without injury to the tissues. _Formulæ for coarse Injections._ _Red._--Yellow bees-wax, 16 ℥. White resin, 9 ℥. Turpentine varnish, 6 ℥. Vermilion, or carmine, 3 ℥. _Yellow._--The same materials, substituting for the red colouring matter, King’s yellow, 2-1/2 ℥. _Black._--Substituting lamp-black, 1 ℥. _Green._--Substituting crystallized verdigris, 4-1/2 ℥. Best flake white, 1-1/2 ℥. Gamboge, 1 ℥. _White._--Substituting fine white bees-wax, and best flake white, 5-1/2 ℥. _Pale blue._--The same, substituting fine blue smalt, 3-1/2 ℥. _Dark blue._--Substituting blue verditer, 10-1/2 ℥.