THE USE OF BLOTTING-PAPER FOR RECONSTRUCTIONS WILLIAM SNOW MILLER1 College of Medicifie, University of Wisconsin, Madison, Wisconsin POUR FIGURES For many years, the Born method of making reconstruction models from wax plates was used, and is still used, iii many laboratories. All of the earlier work was done by this method and excellent results were obtained. In 1905, Susanna Phelps Gage demonstrated at the meeting of the Association of American Anatomists models made from blotting-paper, and since that time this material has been frequently used. Some of the difficulties encountered in the use of wax are the preparation of the plates, the liability of the reconstruction to warp or sag in warm weather, its fragile condition in cold weather, and the difficulty in its use f o r teaching purposes. With a properly constructed tank, the first difficulty is largely overcome, and the addition of various substances to the wax and the introduction of wire supports make the model more rigid. When the model is enclosed within a glass covering, firmly attached to a revolving base, the liability of injury by students is reduced to a minimum. Another difficulty is encountered where it is desired to transport a wax model to some distant point f o r demonstration at a scientific meeting. Railway and hotel porters are not the most careful handlers of fragile material. The following methods of reconstruction with blotting-paper were developed in connection with work done under grants from the National Tuberculosis Association. 191 192 WILLIAM SNOW MILLER While, by varying the quantity of wax, plates of the desired thickness may be obtained, it is not always possible to obtain blotting-paper of the required thickness. This is not, however, a serious handicap to its use. Mrs. Gage has given in her communication explicit directions by which this may be overcome, either by using extra sheets of blotting-paper at regular intervals or, what is less desirable, omitting a section. The most serious difficulty I have encountered is the unwillingness of manufacturers to supply large sheets of blottingpaper. This can, however, be overcome by placing the sheets of blotting-paper end to end and then ‘breaking joints’ as the model is built up. Mrs. Gage, at first, used an ordinary sewing machine for cutting out the parts which had been traced on the blottingpaper ; later, she used an electric sewing machine. F o r some time I used such a machine to which a special pulley was attached, thus increasing its power. With this adaptation I was able to cut with ease through eight superimposed sheets of blotting-paper, each sheet having a thickness of 1 mm. This arrangement worked satisfactorily so long as the model did not require large sheets of blotting-paper; but when large sheets were used, the distance between the needle of the sewing machine and the supporting arm was too short, and great difficulty was encountered. This necessitated rolling or bending the sheets of blotting-paper and not infrequently occasioned cracking of the sheets. I n looking for some other means f o r cutting out the parts from large sheets of blotting-paper and at the same time be enabled to keep the sheets flat during the cutting, I came across an advertisement of the ‘‘Cutawl” manufactured by the International Register Co., of Chicago, Illinois. This instrument (fig. 1) slides easily over the surface of the blotting-paper and the necessary skill in its manipulation is soon acquired. An example of the work done by the “Cutawl” is shown in figure 3 ; the figures are cut out of ten superimposed sheets of blotting-paper, 1mm. thick, each sheet 19 X 24 inches. No BLOTTING-PAPER F O B RECONSTRUCTIONS 193 attempt has been made t o smooth the cut surfaces; they are left just a s they were when the cutting was completed. F o r fastening together the parts cut out from blottingpaper, Nrs. Gage says, “ N o kind of paste o r glue W R S found suitable for this purpose.” She advised the use of “ribbon pins, ordinary piiis, o r wire iiails of various sizes.” My own Fig. 1 Cutawl. Originally designcd for use by display and model wnrkmm. F i g . ? 1)umore surgical engine. A foot control which allows three different speeds is also a p a r t of the equipment. experieiicc is different. T use “Stickine,” a product of the Diamond Ink Co., diluted with water to the consistency of thin cream. Tt is necessary that the two surfaces which come in contacat with each other be well saturated with the mixture and that they he firmly pressed together. If “ Stickine” be iiot available, the following formula makes an excellent substitute: Flour, 2 ounces; powdered alum, 4 ounce. Mix with water t o form a thiii paste, breaking up any T H E A N ~ T O Y ~ C A TRBCOIID, I V O L . 46, NO. 1 194 \VILLIAM SNOW MILLEI: lumps. Add one pint of water arid heat gradually in an enameled dish. As it becomes warm stir occasionally, and as soon as it boils, stir continuously for five minutes. At the end of this time it sl~ouldform a thick paste. Keep in glass jars. One should iiot build small pieces too high without permitting them to d r y ; otherwise, they a r e liable to slip. When Fig. 3 Example of work done by th c cutawl, from a section of the human lung. dry, the various parts of thc model can be reinforced by the insertion of wire which may vary in size depending 011 the size of the part. F o r the insertion of the wire, I use a very handy maehiiie designed especially f o r surgical and dental use-the “Dnmore Geared Surgical Engine. ” With this (fig. a),holcs can be drillcd in the parts and wire, previous1:dipped in Du Pont’s household cement, inserted. Braces and temporary bridges can also be inserted, the holcs being drilled by the surgical engine. BLOTTING-PAPER FOR llECONSTRUCTIONS 195 At times it is necessary to fill in some irregularity in cutting out the parts. F o r this purpose I used, at first, blottingpaper ground t o a fine powder in an old-fashioned coffee mill. This proved a tedious process. I n time the cutting teeth of the mill became so worn, due t o the close contact of the disks, that it 110 longer fuactioncd. Fortunately, the United States Forest Product Laboratory was situated near by and I took my problem there. They furnished me with “Fluffed Burgess Pulp (Sulpliite).” a satisfactory substitute f o r the ground blottinq-paper. When either of these is thoroughly mixed with the diluted “SticBine” to the consistency of a soft putty, Fig. 4 P a r t of a reconstruction t o demonstrate the combination of blottingp a l m a n d ‘magnet wire. ’ Pulmonary artery, dark gray; sulrdirisions of the bronchial t r w , grayish white ; lymphatics, white. Threc-sevenths of the actual size. (From Amcr. Rev. Tubrrr., vol. 18, p. 382.) it can be iised t o fill the irregularity or t o reinforce some weak point in the model. They dry as quickly a s the blotting-paper and become exceedingly firm. I have also used this mixture somewhat thicker in consisteiicy to malie free-hand models. When dry, they are capable of standing rough usage. If the model be small, the entire model may be immerseiI in ‘melted parafin and left in it until no more bubbles rise to the surface. It may then be allowed t o drain and, when cold, can be polished and the various parts colored. If the model be a large one and capable of being taken apart, the various parts mav be treated with paraffin and later reassembled. If the model will n o t allow being taken apart, hot paraffin can be applied by means of a brush. 196 WILLIAM S N O W MILLEB Small blood vessels, lymphatics, and nerves are best made of ‘magnet wire’ coated with either wax o r paraffin. A portion of a model constructed from blotting-paper and magnet wire coated with wax is shown in figure 4. Complete models constructed in the above rnaiiiier are illustrated in stereos I and 11, American Review of Tuberculosis, vol. 18, p. 373. CAUTIONS TO BE OBSERVED I N MAKING MODELS FROM BLOTTING-PAPER Keep in miid the structure of blotting-paper and do not attempt to readjust partly dry pieces; wait until they are d r y ; then cut out the necessary parts with a fine saw, cover them with paste, and place in proper position. Do not attempt to drill holes in any part of a model until it is thoroughly dry. If bridges are used, keep them in place until all the connected parts are d r y ; do not cut them away until all danger of displacement is past.