Notes and Memoranda. 399 



small price, and replace the clumsy and objectionable " live-box." In size and 

 shape the Cheap Compressoi'ium resembles two ordinary gbss slides, one overlying 

 the other. It is made of two pieces of brass — one carrying the cover, and the 

 other the glass bed. It is raised by springs, and depressed by two screws easily 

 worked. We have tried it with various objects, and can recommend it. As soon 

 as an approximation to contact is obtained, the screws must be worked alter- 

 nately, and very gently. Mr. Curteis' slide-cells are modifications of a plan 

 introduced by Mr. Eichard Beck. The cell is formed in an ordinary slide, with 

 or without a back, according to its depth. The cover turns upon a pivot. They 

 work well, provided the cover is quite free from grease ; and this condition is 

 easily obtained by washing it with a little caustic soda. 



Day View of Ventjs with Small Telescope. — Mr. Levander, of Canon- 

 bury, writes to us, that on the 20th of October, 2h. 50m., he saw Venus when 

 only about 25m. 56s. east of the sun, and 9""6 in diameter, with an inch and a 

 half telescope, mounted equatorially by himself, and a power of about 90. A 

 cloud obscured the sun at the time. 



Test poe Ozone. — During a recent discussion at the French Academy on the 

 difilculties of Ozonoscopy, M. Le Verrier stated that, when the subject was 

 discussed last May at Metz, M. Schonbein pointed out that a colourless solution 

 of the protoxide of thallium became yellow under the influence of ozone, and was 

 not, like the iodine test, affected by nitrous compounds ; but, unfortunately, the 

 subject was not yet brought to a practical state. 



Feee Sulphueic Acid in Molltjse:s. — In addition to the Dol'mm galea, 

 MM. St. Lucca and Panceri inform the French Academy that they have dis- 

 covered free sulphuric acid in the glands of Tritonium corrugatum, T. cutaceum, 

 and T. Mrsutum, Cassis sulcosa, Cassidaria echinophora, Murex trunculus, M. 

 Irandaris, Aplysia cornatus, and others (not named). They observe — " Free 

 sulphuric acid is thus found to be an element necessary to the organic functions 

 of a numerous class of mollusks, living in stony localities, and carrying a shell 

 formed almost exclusively of carbonate of lime, accompanied by traces of 

 carbonate of magnesia. The strong acid is found in company with a weak acid — 

 carbonic." 



Electricity and Vegetation. — M. Ch. Blondeau states ("Comptes Eendus," 

 "Nov. 4, 1867), that subjecting fruits — apples, pears, and peaches — to the action 

 of an induced electric current hastens their maturity. Having rendered seeds 

 good conductors by moistening them, he affirms that electrizing them by induced 

 currents causes them to germinate earlier than similar seeds not subjected to such 

 action. He says, " Some haricot beans which were electrized exhibited a singular 

 peculiarity. They germinated head downwards, and root upwards, in the air. 

 That is to say, the gemmule, surrounded by its cotyledons, remained in the 

 ground, while the root, separated by a little stem from the gemmule, erected itself 

 in the air. This fact appears important, as explaining the reason why plants 

 push their roots into the earth, and their stems into the air. This tendency is so 

 strong, that efforts to cause them to act otherwise are fraitle3s ; but it may be 

 overcome by the electric shock, in the same way as the poles of a magnet may be 

 reversed. "We are tempted to liken the embryo to a small magnet with opposite 

 poles." 



Hybbid Cotton. — M. J. E. Balsamo states (" Comptes Eendus") that, by 

 artificial fecundation, he succeeded in obtaining hybrids between the Nankin 

 cotton-plant and the Gfossypium harhadense, and vice versa. In both cases the 

 cotton obtained was of a character intermediate between the two types. 



Light and Vegetation. — The same observer planted cotton-seeds in a glass 

 vessel at various depths of garden mould, and in contact with the glass side. 

 Some were protected by yellow paper gummed to the glass, and others left exposed 

 to the light. The former began to grow in nine days, while the latter were found 

 to be slightly decayed at the end of ten days. 



New Mud-pish peom New Zealand. — In " Annals Nat. Hist." for November 

 Dr. Gtinther describes a new mud-fish sent to the British Museum by direction of 

 Sir G. Grey. It is about 5J inches long, possesses the general characters of 

 Galaxias— scaleless fresh- water fishes, of which five out of twelve known species 

 belong to New Zealand, New South Wales having three, and Van Dieman's Land 



