Whilst pursuing practical anatomy in the University of Pennsylvania, in the year 1814, under the direction of Professor Wistar, I became acquainted with a material for many years known in that institution under the denomination of “_Spalding’s Cold Injection_,”[U] used for the purpose of filling the bloodvessels, without the preparatory measure of heating the subject or the injection ingredients--its use exacted great care on the part of the manipulator, and frequently failed; although, when successful, it surpassed all other coarse injections in minuteness. It was composed by grinding white lead and red lead, of each 4 ℥, in a sufficient quantity of boiled linseed oil to form a thick paste, adding, just previously to injecting, turpentine varnish 8 ℥. [U] Dr. Spalding was a native of Massachusetts, and a student of the late Professor Rush, some thirty or forty years ago. Dr. Parsons gives the following formulæ for cold injections. (_Vide Parson’s Anatomical Preparations_, p. 2.) “_Cold coarse Injections._--This kind consists of colouring matter ground in boiled linseed oil upon a painter’s marble, and made of the consistence of white lead, ground in oil. After being finely levigated, a little lime water, in proportion of two table spoonsful to a pint, is to be incorporated by stirring. At the moment of filling the syringe with the injection, there should be added to it about one-third of its measure of Venice turpentine, which should be stirred quickly, and used immediately, as it very soon hardens. The use of the lime water is to harden the injection; but when white lead (which is almost always adulterated with carbonate of lime) is used, lime water is unnecessary. “_Cold fine Injections._--The same materials will answer, only adding to the Venice turpentine an equal quantity of spirits of turpentine. This is generally thrown in the vessel in small quantities at first, and followed by the above coarse injection. “_Cold minute Injection._--This may be the same as the warm minute injection; or it may consist of vermilion ground very fine in spirits of turpentine, adding a small portion of Venice turpentine, the whole being as fluid as milk, and when thrown in, should be followed by the cold coarse injection.” _Swan’s cold Injection._ This consists of plaster of Paris, to which some colouring matter has been added, and water gradually poured on it until reduced to the consistence of cream--taking care to cleanse the syringe immediately after injecting. For making corroded preparations of the kidney, &c., the _fusible metal_ may be thrown into the artery, after heating the organ (but not the artery) until it acquires the temperature of boiling water--to be afterwards treated as directed in this volume.