THE ART OF THE PERFUMER 255 the skin and with it most of the offending aromatics, but in a toilet water, the oil being left on the skin gives rise to a certain amount of irritation, which is very variable. I regret not mentioning this it was certainly an oversight. The terpeneless oil acts in a similar manner, although I consider the effects much milder. • MR. R. T. DOBSON: IS the odour value of a perfume in soap affected when the soap contains titanium dioxide ? TaE LECTURER: The odour of a perfume in soap is affected a little when the addition of titanium dioxide is made. It is difficult to offer a correct explanation, but one can only presume that certain components of a perfume are adsorbed by the titanium dioxide. The differences are very slight and vary from perfume to perfume, and in some instances the difference is for the better and is preferred. MR. F. W. BELLAIRS .' Benzyl alcohol has been mentioned as an irritant, but surely the effect is anaesthetic rather than irritant ? TaE LECTURER: BenZyl alcohol has definite irritant qualities and is sometimes claimed as being a cause of dermatitis. The excessive use of benzyl alcohol in preparations being rubbed into the skin, or inhaled, should be avoided. DR. W. MITCHELL .' When an "optical bleach" is present in a perfumed detergent, does it, because its declared purpose depends on the absorption of incident ultra-violet radiation, have an effect in protecting the perfume from the harmful effects, if any,. of such radiation ? THE LECTURER: I have not studied this action to any extent. On one or two occasions I have had cause to look into this question, each occasion relating to perfume in soap and not detergent, but without any conclusive results. The question is a very interesting one and it is my intention to pursue this matter more fully. MICROCARD EDITIONS OF THE JOURNAL Vols. I to VIII incl. are now available in microcard form. A complete set, a single volume or a single journal may be ordered from Iota Services, Ltd., 38, Farringdon Street, London, E.C.4. The current and future volumes of the Journal will also be available on microcards, in the year following that of publication.

THE ART OF THE PERFUMER 255 the skin and with it most of the offending aromatics, but in a toilet water, the oil being left on the skin gives rise to a certain amount of irritation, which is very variable. I regret not mentioning this it was certainly an oversight. The terpeneless oil acts in a similar manner, although I consider the effects much milder. • MR. R. T. DOBSON: IS the odour value of a perfume in soap affected when the soap contains titanium dioxide ? TaE LECTURER: The odour of a perfume in soap is affected a little when the addition of titanium dioxide is made. It is difficult to offer a correct explanation, but one can only presume that certain components of a perfume are adsorbed by the titanium dioxide. The differences are very slight and vary from perfume to perfume, and in some instances the difference is for the better and is preferred. MR. F. W. BELLAIRS .' Benzyl alcohol has been mentioned as an irritant, but surely the effect is anaesthetic rather than irritant ? TaE LECTURER: BenZyl alcohol has definite irritant qualities and is sometimes claimed as being a cause of dermatitis. The excessive use of benzyl alcohol in preparations being rubbed into the skin, or inhaled, should be avoided. DR. W. MITCHELL .' When an "optical bleach" is present in a perfumed detergent, does it, because its declared purpose depends on the absorption of incident ultra-violet radiation, have an effect in protecting the perfume from the harmful effects, if any,. of such radiation ? THE LECTURER: I have not studied this action to any extent. On one or two occasions I have had cause to look into this question, each occasion relating to perfume in soap and not detergent, but without any conclusive results. The question is a very interesting one and it is my intention to pursue this matter more fully. MICROCARD EDITIONS OF THE JOURNAL Vols. I to VIII incl. are now available in microcard form. A complete set, a single volume or a single journal may be ordered from Iota Services, Ltd., 38, Farringdon Street, London, E.C.4. The current and future volumes of the Journal will also be available on microcards, in the year following that of publication.