94 GIBBS. 



people, is absent. Moreover, it has been shown that oxyhsemo- 

 globin is transformed into methsemoglobin by ultra-violet light, 

 and while no blood examinations were made upon the subjects 

 described in this paper, later examinations made in Manila 

 indicate that this effect may be produced in the living body by 

 sunlight. I have found methsemoglobin in two cases where a 

 series of animals were exposed in Manila. The difficulties en- 

 countered in positively detecting small quantities of methse- 

 moglobin in presence of oxyhaemoglobin have delayed the com- 

 pletion of this work and any further statement of results or 

 conclusions at this time would be premature. 



With animals the skins of which are practically devoid of 

 sweat glands, death comes upon exposure to the sun; and even 

 monkeys having a considerable number of sweat glands,*' but 

 with a dark protective covering of hair, die in less than one 

 hour, in our observations with temperatures of almost 50° in 

 one case and over 50° in another, measured directly under the 

 skin. Rabbits with black hair died in about thirty minutes 

 showing temperatures between 40° and 50° measured directly 

 under the skin ; those with lighter-colored hair survived a longer 

 time, but were unable to resist continued exposure. 



The striking advantages in lower rate of heat absorption which 

 the white hair has over the darker colors is very suggestive in 

 the consideration of the question of clothing which will be taken 

 up later. 



EXPERIMENTAL. 



The thermocouple employed by Aron and described by him 

 was used. His measurements were made by warming the ther- 

 mometric junction in the palm of the hand and then placing it 

 on the part of the skin to be measured. He states : 



"The metal leaf must lightly touch the skin, and must be kept at one 

 place until the galvanometer just reaches its maximum deviation; with 

 my apparatus twenty seconds were almost more than sufficient for this 

 purpose." 



It is evident that if the skin temperature is lower than the blood 

 temperature, too long a contact with the measuring apparatus will give 

 too high values, while if the skin temperature is higher than the blood 

 temperature the reverse will be the case. I found that the most accurate 

 results were obtained by commencing the measurements a short distance 



* Doctor Shaklee, of the department of pharmacology, University of the 

 Philippines, has investigated this question, and will report upon it. 



