Intelligence and Miscellaneous Articles. 415 



looking forward to brighter sunshine, when I have not the least 

 doubt that I shall obtain sharp fiduciary lines in the ultra-red. 

 The addition of any colour to the preparations has been any thing 

 but beneficial, retarding the action greatly; and, from what is 

 apparent, the virtue of the dyes used consists simply in the fact 

 that they are hydrocarbons of some kind, probably combined with 

 the faint traces of silver always left in the film of the sensitive 

 plate. 



Experiments with potassium bichromate have also been under- 

 taken ; and the result shows that (where partially insolated) the 

 rays which usually have no effect on the sensitive compound are 

 capable of continuing the action set up, as I pointed out in the 

 year 1872. Iron and uranium have also yielded prolonged spectra. 



The first experiments were carried out with a single prism of 

 60°, and a lens to the camera of 4-feet focus ; the later experi- 

 ments have been made with a direct-vision spectroscope of 9 

 prisms, being equivalent to about three single prisms, and with 4 

 prisms in battery. The same camera and object-glass have been 

 employed. — Monthly Notices of the Royal Astronomical Society, 

 March 1876. 



ON THE OCCURRENCE OF PHOSPHATES IN THE CAMBRIAN ROCKS. 

 BY HENRY HICKS, ESQ., F.G.S. 

 In this paper the author showed from experiments that the Cam- 

 brian strata in Wales contain a far greater amount of phosphate and 

 carbonate of lime than had hitherto been supposed. The results 

 published by Dr. Daubeny some years ago, and which have since re- 

 ceived the support of some eminent geologists, were therefore proved 

 to be entirely fallacious when taken to represent the whole Cambrian 

 series ; for though some portions show only a trace of these ingre- 

 dients, there are other beds both interstratified with and underlying 

 these series, which contain them in unusually large proportions. The 

 author therefore objects to look upon Dr. Daubeny's experiments as 

 tending in any way to prove that the seas in which these deposits 

 had accumulated contained but little animal life, and that we 

 here approach the borders of the lower limit of organic existence. 

 He contended that the presence of so much phosphate of lime, and 

 also of carbonate of lime, as was now proved by analyses made by 

 Mr, Hudleston, P.C.S., Mr. Hughes, P.C.S., and himself to be 

 present in series of considerable thickness in the Longmynd group, 

 Menevian group, andTremadoc group, showed that animal life did exist 

 in abundance in these early seas, and that even here it must be con- 

 sidered that we were far from the beginning of organic existence. 

 The amount of phosphate of lime in some of the beds was in the pro- 

 portion of nearly 10 per cent., and of carbonate of lime over 40 per 

 cent. The proportion of phosphate of lime, therefore, is greater than 

 is found in most of what have been considered the richest of recent 

 formations. The amount of P 2 5 was also found to increase in pro- 

 portion to the richness of the deposit in organic remains. It was 



