42 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS sweat output, say the last 25 min in the warm-room, much of the antiperspirant is being washed off the skin. On the other hand, if the ant•iperspira•a.t is an a!uminium salt, the sugges,ted mechanism is that it alters the physiology of the duct to some extent, so that there is leakage of sweat into the axillary skin around the sweat o•tlet. In warm-room studies the antiperspirant has already made this alteration to the sweat duct when the measurements are being made. If this is the mechanism the effect, presumably, should last quite a considerable time, even if residual antiperspirant is washed from the skin surface. MR. M. K. SHEPHERD: Normally, roll-on deodorants are supposed to last longer than the dry antiperspirants. Was this so in your experiments? THE LECTURER: I have no experience of dry antipe•rspirants. Under experimental conditions we are making measurements within 2-3 h of the time of application of the antiperspirants. ,DR. D. JACKSON: You h, ave mentioned that stimulation of eccrine glands can be achieved by iontophoresis of pilocarpine. I wonder if you have any evidence suggesting an adrenergic mechanism of sweat control or production. One group of workers who have used iontophoresis compared nor-adrenaline plus pilocarpine with pilocarpine alone. In the former case there was a significant increase in concentrations of sodium chloride in sweat and they suggested that this type of mechanism may also be in- volved as well as the cholinergic ones. Have you any comments to make on this possibility? THE LECTURER: Are you suggesting that one should control sweat by using an anticholinergic agent? DR. D. JACKSON: Not directly. I wondered if you foun. d any evidence to suggest an ad.renergic method of sweat control in addition to the cholinergic one. THE LECTURER: We have done no work on this aspect: this paper is a review of the methods that are available for antiperspirant evaluation. Our own methods and the materials we have studied are purely the commonly available ones, such as aluminium salts. It is possible that eccr•ine sweat glands have duai innerration with cholinergic and adrenergic nerves supplying them, but we have not investigated this. MR. N.J. V•.N A• BBI•: The literature seems to be more firm in suggestin, g ad.renergic innervation of the apocrine glands rather than the eccrine glands. I think it would be generally accepted •that the eccrine glands primarily concerned with sweat are cholinerg!c, but there is some doubt about the apocrine. DR. D. JACKSON: Yes, this is relatively new information. I think the authors were pointing out that eccrine glands were previously thought to be ch01!nergic in the main, but their recent evidence seems to suggest that adrenergic mechanisms may also be involved in the control of these glands. MR. N.J. VAN ABBI•: I think it is well established that an ant.i-cholinergic drug will give 100% inhibition of eccrine sweat for õeveral days. But the {xi!lary eccrine glands are not as much affected as glands in other parts of the body. I'have not seen an explanation for this difference. " , PROF. F. J. EBLIN•: • do not kqow why this should be, but I should like to add the

MEASUREMENT AND CONTROL OF PERSPIRATION 43 comment that maybe there is more than one type of eccrine gland. It seems pertinent to me that a high proportion of mammals have eccrine foot-pad glands. On the other hand, eccrine glands are seldom present in hairy skin. It seems to me a surprising fact that the eccrine glands on the hand and foot develop much sooner in the foetus than the others, and I suspect that there are at least two phylogenetically and physio- logically different types of eccrine glands and perhaps even more. DR. D. JAcKsoN: The workers to whom I previously referred, have suggested this delineation of two types of eccrine gland and have suggested that possibly the adren- ergic mechanism may be responsible for producing different types of sweat in the glands of the palms and the soles compared with the eccrine glands in other parts of the body.