382 Meteorological Ohseivationsfor Fehntary 1838. 



nomena. M. Dumas observes that there are a class of phsenomena 

 which have a tendency to become general, and which seem to 

 follow a law which may be expressed as follows : 



In citric, tartaric, meconic, and cyanuric acids, each equivalent of 

 oxygen belonging to the bases to which they are united can dis- 

 place and replace an equivalent of oxygen, which disappears in the 

 state of water. These acids therefore do not form salts with excess 

 of base, but salts of the same order as ordinary phosphates. 



These remarkable phaenomena may be looked upon in a more 

 simple and general manner by considering these acids as hydracids 

 of a new kind. Tartaric acid, for example, being considered as it 

 has hitherto been, will give the following formulas : 

 C8 H4 0\ real acid. 

 Cs H4 0% H2 O hydrated acid. 

 C8 H^ 0\ K O neutral tartrate of potash. 

 C« H^ 0\ K 04-C8 H^ 0\ W O cream of tartar. 

 2 C« H^ 0^ + K O + Sb2 03 tartar emetic. 

 These complicated formulas become very simple when represented 

 in the following manner : 



C16 H* 012 H8 hydrated acid. 



Q\6 H* 0'3 I ^4 I neutral tartrate of potash. 

 Q\6 H* 0'2 I j^g j cream of tartar. 



Q^iQ H* 0'2 1^2 j anhydrous tartar emetic. 



It may therefore be observed that dry tartaric acid does not exist, 

 and that a radical C'^ h* O^^ must be admitted, which with H^ 

 would constitute an hydracid of a new kind. 



If this is admitted, all the combinations of the radical tartrate will 

 be represented by saying. 



That in all these combinations hydrogen is replaced either alto- 

 gether or in part by its metallic equivalents, as it is presented in all 

 its analogous substitutions. We could show without difficulty that 

 the constitution of the citric, meconic, and cyanuric acids is sub- 

 ject to the same transformations, and that they could be also repre- 

 sented as hydracids. 



In our memoir is contained an experimental discussion under this 

 new point of view, which will give the opinions of M. Dulong 

 concerning oxalic acid an unexpected extension. — L'Institut, Jan. 

 1838. 



METEOROLOGICAL OBSERVATIONS FOR FEBRUARY 1838. 

 Penzance. — The greater part of this month has been extremely 

 boisterous and rainy ; scarcely a day has elapsed without a storm, 

 which has generally been of short continuance, except in two in- 

 stances, when it continued — in the former, on the 14th, 15th and 16th 

 iust., with unabated fury for upwards of 40 hours, accompanied with 

 an astonishing quantity of rain, amounting to two and a half inches. 

 The wind during this period blew from SSE. to SE. The mercury 

 was not so low in this instance as it was at the last great storm, on 



