I told you yesterday that, notwithstanding the tremendous heat of the weather, we were going to a large party in the evening. We courageously kept the engagement; though, I assure you, I did it in trembling. But, to our equal surprise and satisfaction, the rooms of Mrs. M---- proved to be deliciously cool and agreeable. Her receiving-apartment consists of three rooms. The first was surrounded and decorated in all possible ways with a profusion of the most beautiful flowers, intermixed with so many large glass vases for gold fish, that I am sure the air was much cooled by evaporation from the water they contained. This room was lighted wholly by a large lamp suspended from the ceiling, which was enclosed in a sort of gauze globe, just sufficiently thick to prevent any painful glare of light, but not enough so to injure the beautiful effect always produced by the illumination of flowers. The large croisées were thrown open, with very slight muslin curtains over them; and the whole effect of the room--its cool atmosphere, its delicious fragrance, and its subdued light--was so enchanting, that it was not without difficulty we passed on to pay our compliments to Mrs. M----, who was in a larger but much less fascinating apartment. There were many French persons present, but the majority of the company was English. Having looked about us a little, we retreated to the fishes and the myrtles; and as there was a very handsome man singing buffa songs in one of the other rooms, with a score of very handsome women looking at and listening to him, the multitude assembled there; and we had the extreme felicity of finding fresh air and a sofa _à notre disposition_, with the additional satisfaction of accepting or refusing ices every time the trays paraded before us. You will believe that we were not long left without companions, in a position so every way desirable: and in truth we soon had about us a select committee of superlatively agreeable people; and there we sat till considerably past midnight, with a degree of enjoyment which rarely belongs to hours devoted to a very large party in very hot weather. And what did we talk about?--I think it would be easier to enumerate the subjects we did not touch upon than those we did. Everybody seemed to think that it would be too fatiguing to run any theme far; and so, rather in the style of idle, pampered lap-dogs, than of spirited pointers and setters, we amused ourselves by skittishly pursuing whatever was started, just as it pleased us, and then turned round and reposed till something else darted into view. The whole circle, consisting of seven persons, were English with the exception of one; and that one was--he must excuse me, for I will not name him--that one was a most exceedingly clever and superlatively agreeable young Frenchman.