Intelligence and Miscellaneous Articles. 1 65 



He concluded by stating, that as creatine is found in the urine 

 along with creatinine, it appears to he, in part at least, a substance 

 intended for excretion. Its crystalline character renders this pro- 

 bable ; and at all events, if it has any function to perform in the 

 body, that function is not yet known. It must be regarded, in the 

 mean time, as one of the numerous series of less complex products 

 derived from the decomposition, in the body, of the effete tissues ; 

 and although we cannot yet produce it artificially, yet from the rapid 

 progress recently made in the study of the products of decomposition 

 of the albuminous substances, we may hope soon, not only to do 

 this, but also to discover, from these products, the true formulae of 

 the albuminous compound. — Ibid. 



RESEARCHES ON THE CONSTITUTION OF THE ATMOSPHERE. 



M. Doyere having had particular occasion to examine the phse- 

 nomena of respiration of man and animals exposed to the influence 

 of the vapour of aether, he was induced to try the protochloride of 

 copper as an absorbent of oxygen in gaseous mixtures. The favour- 

 able results of the employment of this reagent having induced him 

 to pursue the study of eudiometry, he succeeded in effecting a com- 

 bination of instruments with simple means of correction and easy 

 management, which gave the original volume of a gas, and that of the 

 residue which any absorbent leaves, within a ten-thousandth part. 



The author was surprised to find that his method indicated larger 

 proportions of oxygen than those generally admitted, and that even 

 among them considerable variations occurred. M. Doyere continued 

 his operations for four months, and the results proved that the com- 

 position of the air varies incessantly. In general the variation is 

 slight, and the proportions of oxygen varying between 208 and 210 

 parts in 1000 ; but this variation was found to go as low as 205, and 

 as high as 212. These great differences never occurred suddenly ; 

 the quantity having diminished or increased as gradually as consists 

 with such a description of facts. M. Doyere shows that his results 

 harmonize perfectly with those of MM. Boussingault and Dumas 

 obtained at Paris ; — with those which were obtained by M. Stas at 

 Brussels, and with the great work achieved by M. Lewy with respect 

 to the air of the North Sea, and that of Guadaloupe. He also proves 

 that Dr. Prout's experiments on the weight of the air, and those 

 published by M. Regnault, agree with his view of the subject, and 

 prove that the air is continually varying. 



He shows also, that the densities of oxygen and nitrogen given by 

 M. Regnault do not agree with the composition of the air when 

 stated to contain only 209 of oxygen ; and that they indicate 213 

 thousandths of oxygen if the mean density of nitrogen be adopted, 

 and 212 to 215 if the extreme densities resulting from the experi- 

 ments of M. Regnault be preferred. — Comptes Rendus, Fevr'ier 14, 1848. 



RESEARCHES ON ESSENTIAL OILS. BY M. C. GERHARDT. 



Oil of Chamomile (Anthemis nobilis). — This oil, like the greater 

 number of liquid essential oils, is a mixture of two principles, one 



