Handbook of the Hospital Corps, United States Navy, 1939 / published by the Bureau of Medicine and Surgery under the authority of the Secretary of the Navy.

Date:
1939
Catalogue details

Licence: Public Domain Mark

Credit: Handbook of the Hospital Corps, United States Navy, 1939 / published by the Bureau of Medicine and Surgery under the authority of the Secretary of the Navy. Source: Wellcome Collection.

    973/1036 (page 959)
    or increasing the developing time approximately 20 seconds for each degree of change in temperature, normal development may be accomplished in tempera- tures ranging between 60° F. and 70° F. Below the former or above the latter temperature, development should never be attempted unless in specially pre- pared solutions. Powders compounded in the proper proportions are issued to all naval activi- ties having X-ray facilities. The developing solution should be prepared as outlined in the instructions appearing on each container. Distilled water should _be used if practicable. There are several cautions that must be observed in mixing processing solu- tions. The vessels or pails should be made of glass or enamelware, for metals, such as galvanized iron, tin, copper, zinc, ete., will cause contamination, and re- sult in fog in the radiograph. After development, the film should be rinsed for about 30 seconds in clean, running water to remove as much of the developing solution as possible. If the film is transferred directly to the fixing bath from the developer, the alkali from the former solution retained on the film will neutralize some of the acid in the fixing solution. After a certain quantity of acid has been neutralized, the bath has lost its chemical balance; the hardening action is destroyed and stains are apt to appear on the radiograph. The purpose of fixation is to remove all unexposed silver salts from the emulsion and to fix permanently the image that has been brought out by the developer. The fixing bath contains not only the fixing chemicals but also those chemicals that harden the gelatin of the emuision, and it permits ordinary handling and filing of the film without damage. The fixing solution ordinarily used in the naval service is prepared as follows: Acip Frx1inc BATH Sodimhypoculite: chy po”) 2o 8 ee 2 lb. 8 02. INCCTIC MCL? S70 Le) 20. Te es ee a ee Boze SSO SUT EI GSTS* | ESUUN II] (Ss Par SC ge ee ea ROD ee ge fe fuer eel oer 1.6 oz. EO SSUSSSO TEC 23 0 11 ln Ho payer pec aes 1.6 oz. eel POC et a ee es ee ee ae 1 gal. (To make 28% acetic acid from glacial acetic acid, take 3 parts of glacial acetic acid and add 8 parts of water.) To prepare the bath, dissolve the “hypo” in 48 ounces of water. The water used in dissolving the different ingredients should be at approximately 125° F. Dissolve the sodium sulfite in 32 ounces of water and when it is thoroughly dissolved, add the acid. Dissolve the alum in 32 ounces of water and mix with the sulfite-acid solution. Never add the alum before the acid, or a milky pre- cipitate will result. Now mix the two solutions and add sufficient cold water to make 1 gallon, and stir. The solution must be free from debris and clear. If a milky precipitate results, known as sulfurization, an error has been made in the preparation and the solution should be discarded. Proper fixation has occurred when the film is left submerged in the fixing solution twice as long as is required to remove all trace of the opalescent silver salts. This usually requires from 15 to 30 minutes, depending upon the strength and condition of the solution. After fixation, the film should be washed in running water which is so circu- lating that all parts of the film and hanger receive frequent changes. If the hourly flow in the tank is 4 times the tank capacity, 30: minutes’ wash will be