The influence of ultra-violet rays on industrial output / by A. Lisle Punch and Russell Wilkinson with the collaboration of R. StC. Brooke and C.S. Myers.

  • Punch, A. Lisle.
Date:
1928?]
Catalogue details

Licence: In copyright

Credit: The influence of ultra-violet rays on industrial output / by A. Lisle Punch and Russell Wilkinson with the collaboration of R. StC. Brooke and C.S. Myers. Source: Wellcome Collection.

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    Treatment was given daily at 8 a.m. for four weeks. Of the 12 treatments the first four were on consecutive days, while in the second week three treatments, in the third week three treatments, and in the fourth week two treat¬ ments were given to each girl. Exactly the same procedure was carried out on the controls. The initial exposure was two and a half minutes for the whole body, back and front. Thereafter the exposures were increased gradually up to thirty minutes, according to the degree of erythema produced in each case. For the first four exposures each patient was treated individually with the air-cooled mercury- vapour lamp. Subsequently the girls were treated in batches of three at a time with the Jesionek lamps. The same lamps were used for the control group, but a sheet of “ triplex ” glass, 5/32 in. in thickness, was placed as a screen between the patient and the quartz burner. The absorption limit of this glass at this thickness being 3300, all the ultra-violet rays were cut off and no rays of shorter wave-length than 400 mm. reached the patient. The findings had to be adjusted owing to the following circumstances : (1) During the pre-treatment and post- treatment periods of observation, the girls worked daily from 8 A.M. to 5.30 p.m. (with an hour off for dinner between noon and 1 p.m.) ; during the treatment period they began work at 9 A.M., as they were under treatment each morning between 8 and 9 o’clock. (2) At the start of each morning and afternoon spell of work the chocolate had to be tem¬ pered, so that the actual manufacture did not begin until 10 or 15 minutes later. (3) A rest pause of about four minutes was given during each spell of work. (4) A period of clearing-up occurred towards the end of each spell.* (5) Temporary absences from the room or from the works had to be allowed for. Table I. — Pre-treatment. Treatment. Post-treatment. A. . . .. 33 C . . .. D .. 96-6 110-2 103-7 117-8 9?:“} 93 7 1K}1083 108-0 1170 107-6 122-0 The eight girls subjected to the ultra-violet rays, whose individual output throughout the three periods was regularly recorded, will be designated respectively by the letters A-H. They fall into two groups : (1) those whose output was evidently increased (A, B, C, D) upon exposure to ultra-violet rays ; * For this and other reasons the output during the last half hour of the day is not reliable ; no records were therefore taken between 5 and 5.30 p.m,